The Ten Commandments of Crossovers
by Lucy Gillam

I love crossovers.  Really, I do.  Done well, they’re among my favorite stories.

The problem is, they’re so seldom done well.

I’ve spent a long time pondering why these stories don’t work, and the results of that pondering are the 10 Commandments of Crossovers, or the do’s and don’ts (mostly don’ts) of mixing sources.

I.   Thou Shalt Not Cross Sources Just Because it Would be “Neat.”

Most crossovers start at the point of “wouldn’t it be neat if X met Y?,”  which is a perfectly valid inspiration for a story.  “Kindred Spirits,” arguably one of the best-loved Sentinel stories ever, was obviously begun as the idea that Blair and Methos would be cute together.

Successful crossovers, however, go beyond just “wouldn’t it be neat” to “what can I do with this that I can’t do with the individual sources on their own?”  Bringing Methos and Blair together, for example, allowed the writer to bring out and explore the unrequited love they feel for their two partners, basing it on the similarities in the personalities and situations.  Although the story is little more than a PWP, it’s filled with character explication and development.

This can actually be seen fairly clearly on the crossovers the tv shows themselves do.  The unsuccessful ones, usually done among sitcoms that all appear on one night, are done with the idea that it would just be “cool” to have someone from show 1 pop up on show 2 (thus, hopefully, getting fans of show 1 or 2 to watch show 2 or 1).  The episodes usually revolve around the single joke of having these characters interact, which, while sometimes amusing, seldom does anything you don’t see on each show every week.

Contrast that with a successful crossover: the crossover between Ally McBeal and The Practice. The fact that both are the creations of the same person probably helped, but it helped even more that David E. Kelly made the most of the opportunity.  He may very well have started out with the notion that it would be “neat” to cross his two Boston lawyer shows (especially since it would cause the networks some headaches), but once he decided to do it, he looked at what about it would be neat.  Giving the Ally lawyers a more serious case than they were used to (a murder case, albeit a quirky one) gave him the opportunity to explore Billy’s ambition and Ally’s fear of high stakes.  Bringing the lighter-hearted Cage and Fish crowd onto The Practice gave Bobby Donnell et al an outsider’s view of their sometimes questionable win-at-all-costs tactics.  In the midst of this, the near-romance between Bobby and Ally was just an entertaining side effect.

Even worse than "wouldn't it be neat" stories are the slash crossovers that serve no other purpose than to have two cute characters boink each other.  Yes, I’m sure Mulder and Sam Seaborne would look yummy together (although part of me cringes at slashing a Rob Lowe character, for reasons that are obvious if you’re old enough to remember that scandal), but that’s not a good enough reason to bring together characters from shows that are not only completely different genres (See Commandment III), but just plain don’t fit.
 

II.   Thou shalt know and represent both thy sources equally.

This is an easy one: just as one should not write a story having only seen one episode of the series (seem Emily Brunson’s The Siren Call), one should not write a crossover if one barely knows one of the sources.

The trick is that knowing one source well sometimes convinces writers that they can fudge on the second.  These stories are usually characterized by lopsided detail – they almost always take place in the locale of the better-known material, and the less-known characters often seem like OC’s with the serial numbers etched on.

For example, Alyjude’s “Homeward Bound” imports Thomas Magnum to Cascade.  Naturally, he turns out to be Blair’s father (see Commandment X).    (Note: the story is not listed as a crossover, but it does fit the definition).  So we have a Magnum with no Hawaii, no zippy red car, no Rick, T.C., no Higgins (they’re only mentioned once, and never appear), and a Magnum who doesn’t sound much like Magnum.  Alyjude knows Magnum well enough to know he had a daughter, and roughly what age she would be, but there’s little else of Magnum, PI in the story.  “Homeward Bound” is a TS story, so there’s no reason to give MPI the same amount of story time.  However, if you’re going to use an existing character, he ought at least to be afford the same level of faithfulness to the original as the other source.  Thus, while I can’t judge how well she knows that source, I can say that the Thomas she writes might as well be an original character.

Now, does this mean that if you know SG-1 forwards, backwards, sideways, can quote eps, know every detail of Daniel and Jack’s background, can talk like Teal’c at the drop of a hat, etc, and you’ve seen every Highlander ep but don’t have them memorized, that you can’t write a crossover until you can quote from “Chivalry?"  No.  But it does mean you need to do your homework to make sure that your sources are represented equally, if not in story time, then in depth of detail.
 

III. Thou Shalt Avoid the Reciting of Mighty Deeds

One of the greatest challenges of crossovers is exposition.  Even if the writer can assume her audience is familiar with both sources (which may or may not be true), the characters themselves generally don’t know much about each other.  Since most crossovers involve characters either meeting for the first time, or meeting for the first time in years, it’s safe to assume that the SG-1 characters won’t know Jim is a Sentinel (although that’s easier after TSbBS), or that Methos would know about the Stargate program.  This need for characters to explain their relative situations has led to a phenomenon other, wiser minds whose names escape my cough-syrup addled brain call The Reciting of the Might Deeds.

You know the scene: Blair explains to Mulder, who is visiting on a case, that Jim is a Sentinel, a person with five enhanced senses.  Mulder explains that he can easily believe this because he investigates cases called X-Files, which deal with the bizarre and unexplained, in his quest to find his sister, who was kidnapped by aliens when he was twelve.

By this point the reader, who knows all this, is either nodding off or expecting Beowulf to charge in.

So how to avoid this?  Well, I have a few favorite techniques.

If your intended audience is familiar with both sources, keep the exposition off screen.  The best way to do that is either to fade out just before the exposition (Jim and Blair in the gate room, staring at the Stargate), or fade in just after the long explanations (Jack expressing his skepticism about enhanced senses).

If you’re less sure about your readers’ knowledge, give the characters enough knowledge of each others situations that they’re talking about it instead of explaining it.  I’ve read several TS/Due South crossovers have accomplished this by making Frasier one of Blair’s early test subjects (and often former lover, natch).  This fits both series, since we know Blair had case studies of people with one or two enhanced senses, and Benton has certainly displayed evidence of one or two senses that are above average.  Moreover, rather than Blair or Jim having to explain the whole concept of a Sentinel, Ben and Blair are able to discuss Blair finding someone with all five senses in a way that lets the reader who doesn’t know the concept figure it out without putting the reader who does know it to sleep.

Remember, too, that over the course of most of these series, very few people learned the truth about the main characters.  How many people did Duncan reveal his immortality to, much less Methos?  And Jim didn't even tell his own brother he was a Sentinel.  Mulder, perhaps, is a little more forthcoming about his work, but there's no reason to think the characters would be spilling deeply held secrets on five minutes' acquaintance.  Yes, it can be frustrating waiting for the secrets to come out, but there's also a certain tension in secrets being kept, too.
 

IV.  Thou shalt not egregiously mix thy genres

I want to clarify first that I’m talking about genre, not medium.  While I’m a huge believer in Marshall Mcluhan’s notion that the medium is the message (one of the reasons I think so few movies based on comic books have been successful is that concepts which work beautifully as a series of still pictures look, frankly, silly when acted out by real people), I do believe that a fan writer can cross sources from different media.  In fan fiction, you have one advantage working for you: for the most part, you’re already shifting media from visual (live action movie/tv, usually, but also comic books and cartoons) to written.  Since writing is one of the more flexible media (witness how many other media are novelized), this shift can let you combine stories from different media that wouldn’t necessarily work otherwise.

So mixing media can work.  Mixing genres almost never does.

Genre, for our purposes, is loosely defined as the category of fiction into which a source fits – sci-fi, crime fiction (mystery, cop show), horror, comedy, drama, etc.  Now, obviously, there are shows that fall into the gray space between genres.  Is The Sentinel a cop show or a science fiction show?  Is the X-Files sci-fi or horror (I like the umbrella term “speculative fiction,” but it falls down when trying to distinguish, say, the Xfiles from Buffy the Vampire Slayer, or on the other end, from SG-1).

These gray spaces give you some wiggle room for crossing shows of similar, but not identical genre mixes.  David E. Kelley was able to mix Ally McBeal (a comedy) with The Practice (a drama) because each had enough elements of the other to make the mix viable.  There is enough oddity in the world of The Practice that Bobby Donnell, while commenting on the weirdness that surrounds Cage and Fish, wasn’t running for the elevator, and enough seriousness in Ally McBeal to allow Ally and Billy to work the courtrooms of The Practice without getting thrown in jail for contempt.

In the fanfic world,  The Sentinel has proven to be amazingly versatile for crossovers because it has enough science fiction elements to cross with shows like SG-1, Buffy, or the X-Files, but not too many to cross with more “mainstream” cop shows like Homicide (although the different tone of the latter makes that something of a challenge).  In a world where a cop with genetically enhanced senses can bring his partner back from the dead and see ghosts, the existence of vampires is not too great a stretch (although once Angel established the existence of substantial demon communities outside Sunnydale, you start to wonder why Jim has never sensed a demon – but we’ll deal with that later).

On the other hand, I have a hard time seeing vampires in the world of The West Wing.  Throwing something supernatural into the world of a conventional drama throws off the expectations of reality.  While this is not always a bad thing, it is seldom a good one. In some contexts, you can say "ta-da, he is really a vampire" and it's possible to buy it. In other contexts, you can say "ta-da, he is really a vampire" and everyone will break down laughing.¹ The West Wing is definitely one of the latter.
 

V .   Thou Shalt Not Mix Contradicting Universes

There are very, very few Star Wars crossovers.  Ever fewer good ones.  Why?  Because the universe is completely incompatible with pretty much every universe in existence.  Besides that “a long time ago in a Galaxy far, far away” thing, you’ve got species, planets, and technologies that just plain don’t exist in any other source.  We’re not talking about a “our world in the future” like Babylon 5 or Star Trek; this is never was and never will be land.  You just can’t have Jedi walking into a bar in Cascade – the whole place would cease to exist from paradox.

Of course, the way writers deal with this little conundrum is through the “alternate universe” theory, or the Portal Principle.  You know the one: Obi-Wan/Luke/Methos/Mulder stumbles across a mysterious circle (often these look much like Stargates).  Purposely or not, Obi-Wan/Luke/Methos/Mulder goes through said portal and finds himself in an alternate universe that, coincidentally enough, contains the other source.

As a practical device for bringing the two universes together, these portals are all well and good.  Whole television shows have been based on the alternate universe theory, and in a world with either Stargates or Jedi Knights, interdimensional portals are not so out there.

However (you knew there was a however coming there, didn’t you?), the Portal Principle doesn’t answer any number of questions.  I can buy the coincidence that the portal would plunk Mulder down right where Obi-Wan can stumble across him, or Obi-Wan right in the middle of one of  Duncan’s swordfights, but … look, we all know Jedi Knights don’t really speak English, don’t we?   You’re taking a character and dropping him (or her, although it’s usually him) into a  completely alien landscape, something the Portal Principle almost never takes into account.  Somehow, within hours, Obi-Wan is moving about 20th-century U.S. culture with ease.  Even a Jedi Knight isn’t that good.

Having said this, I have seen two stories that have successfully pulled off the Portal Principle, for completely opposite reasons.

The first is the fabulous When Hellmouths Collide, a Buffy/Hercules/Xena crossover.  The story begins with Buffy and Co. transported to the ancient Greece of Hercules.  The story works because the writers take the Portal Principle seriously: they actually deal with many of the issues involved.  The language barrier is not resolved for several chapters, and then by a method that fits both universes (magic).  Cultural differences become a source of humor and plot.  Perhaps most importantly, the story makes it clear that this Greece is not the ancient Greece of the Buffyverse; it acknowledges that significant differences exist in the history and mythology of Buffy’s world (the “real” world, in other words).

The other story I’ve seen successfully cross contradicting universes is Eros: A Multiuniverse love story by Brenda Antrim.  This story works for exactly the opposite reason of WHC: it doesn’t take itself, or the Portal Principle, even remotely seriously.  Like her satiric “Party” series, Eros is just a romp, in this case designed largely to allow Obi-Wan to fuck his way through three shows.  Yes, I know I already said that was a bad thing.  It isn’t here.  Why?  Because the narrative makes it clear that Brenda knows how silly this is, knows there’s all kinds of questions not being answered, or even asked, and doesn’t insult the readers’ intelligence by pretending this is remotely plausible.  She simply asks them to come along for the ride.  The fact that she starts and finishes the story with Q, who is the controlling entity, doesn’t hurt.  His segments set the whimsical, “anything is possible, so don’t ask,” tone for the piece.

Now, you’re probably sitting there thinking, “Well, I don’t write Star Wars, so I’m safe.”  Wrong.  There are universe that contradict in more subtle, but equally important ways.

I mentioned earlier that The Sentinel was a safe crossover with Buffy until Angel got his own show and populated a non-Sunnydale city with demons and vampires.  Once the new series made it clear that other cites had not only supernatural denizens, but whole communities of demons and vampires, crossing with a show about a cop with hyper senses becomes problematic, especially if you’re going to posit that Jim’s senses allow him to detect vampires or demons.  If they’ve been there all along, and he can detect them, why haven’t we seen evidence of them before now (now being the time of the story)

Take another example: we know that the President in the world of SG-1 knows about the Stargate project, has spoken with the people involved, and that others in the government know about it.  So, by logic, one would assume that the President occasionally discusses the project with those in the know, at the very least with the closest members of his staff (you see where this is going).  Thus, an SG-1/WW crossover, besides being a bad mix of genres, would have to explain why President Bartlett has never mentioned it.  Given that we’ve seen several episodes dealing heavily with either the military or the space program, that omission would take a lot of explaining.

And sometimes those omissions can be explained.  Perhaps the vampire/demon communities in Cascade know about Jim, and know to avoid him.  Perhaps the President only speaks of the SG program in his most guarded moments, keeping it from everyone but, say, Leo.  Certainly there’s a lot that goes on off-camera – that’s one of the reasons we have fan fiction.

However (yet again <g>), these explanations often fall prey to something I call the Geneva Bible Syndrome.  If you’ve never read it, the Geneva Bible was the first Protestant Bible printed, and has thousands of little notes in the margins that explain that what God/Jesus/the writer really meant was <insert explanation that brings the text in line with early Protestant theology>.  It’s not out of the realm of possibility, but it always strikes me as stretching probability and looooooong way to make a point.
 

VI.  Thou Shalt Not Randomly Mix and Match Pairs

We all know the standard formula for slash crossovers:  Blair/Daniel/Frasier meets Bodie/Mulder/Methos; often they were good friends/lovers at some point in the past.  They have a brief fling, or reminisce about their previous fling.  All this makes Jim/Jack/Ray/Doyle/Skinner(Krycek)/Mac jealous, and causes everyone to fall into the Divinely Appointed couples.

So far, so good.  Nothing outside the realm of standard romance (although see Commandment VII below).

I can almost follow this far enough to accept that Jim/Jack/Ray would be attracted to Doyle/Skinner(Krycek)/Mac, or to Bodie/Mulder/Methos.  It’s when the four men start playing musical beds (or just all fall into one bed together) that I get waves of ick.

Some of this is due to Commandment VII: you’re stretching the realm of possibility to assume that all four men are attracted to other men.  More than that, though, a foursome mix-and-match assumes that each man is attracted to the other three, that all four have some odd ideas about monogamy (you’re the only one for me, but if we do it together, it’s not cheating – I’m not saying that some people might not feel that way, but four of four men in early 21st century America?), that all four are sexually adventurous (all the more improbable in stories where Jim/Jack/Ray has never had sex with a man before – now he’s sleeping with three?)

And that’s a lot of assuming for one little story.
 

VII.  Thou Shalt Not Assume Everyone is Gay

Slash fiction is based on one rather large suspension of disbelief: that two men who are, at least in the surface, heterosexual are either gay and so far in the closet they’re actively dating women to hide, or bi and so far in the closet that they not only don’t date men, but never look at them, or essentially heterosexual, but love each other enough to overcome decades of social conditioning.

Now, for some, there is more disbelief to suspend that others, but we’re still talking about a leap of faith, here (to grossly mix my metaphors).

Slash crossovers almost always require the reader to make that suspension not once, but twice.  That is, we’re not only supposed to accept that Jack and Daniel, who’ve both been married and both expressed sexual attraction to women, could be attracted to one another, but that Jim and Blair are likewise other than the generally heterosexual men we see on screen.

Now, sometimes that suspension of disbelief is the ticket price of the story, the tacit contract we enter into with the writer.  Sometimes, however, the writer hoists the disbelief so high that the suspension cracks.

The most common of these stories are the kind described in Commandment VI – the Mix-n-Match stories.   Others, however, simply suffer from a preponderance of couples.  Mona Ramsey’s “Joe’s Son” series, for example, pairs Jim and Blair, Joe and Richie, and Mac and Methos.  As is that weren’t enough, she eventually mix-n-matches by pairing Blair and Methos.  The stories are well-written enough, but you start to wonder how the human race is surviving if no one’s procreating.

Crossovers aren’t the only stories that fall prey to the “Everybody’s Gay” phenom – we’ve all seen the stories where every denizen of Major Crimes, every immortal, every Jedi Knight, every person at SGC, is paired off with a member of the same sex.  But crossover are particularly vulnerable to it, and as much as I do love seeing True Love triumph, I cherish the occasional story where only one of the pairings realizes they’re just good buds.
 
 

VIII.  Thou Shalt Not Base Thy Crossover On Trivial Coincidences

West Wing recently had a guest character named Congressman Skinner, a gay Republican who met with Josh to discuss an anti-gay marriage bill.

Now, where in Washington D.C. have we seen the name Skinner before?

Never mind that we’ve never heard of Walter Skinner having a brother,  much less one in the legislature (you could argue it was several seasons before we heard he had a wife, although I think a brother in Congress would have been more likely to come up).    Never mind that they’re not the only Skinners on television (I dread the day someone decides Seymour Skinner of Springfield has a brother in D.C.).  Perfect chance for a crossover, right?

Wrong.

There’s certainly something tempting in giving Walter Skinner a gay brother, especially – the story possibilities are quite real – and when another show already provides one, how can the fan writer resist?  Well, for starters, by looking at Commandment III and asking yourself how probable it is that the X-Files in the world of West Wing.  Then by looking at how much we know about Congressman Skinner (he’s Republican and he’s gay – that’s about it) and asking yourself if this would really be a crossover, or a story with an original character who’s had serial numbers thinly engraved on his butt.

Even worse are crossovers that rely on the same actor appearing in both shows.  The actress who played Naomi Sandburg on The Sentinel guest-starred on The Pretender as the mother of Sidney’s long-lost son (I can see the light bulbs firing up now).  Despite the fact that she has a different name, a different background, and a different personality, this casting coincidence has led to several stories in which – you guessed it – Blair is Sidney’s son.

Now, there’s nothing inherently wrong with this if you’re willing to ignore the contradictions in canon (the old AU track), but many of them bring us back to Commandment I: most stories don’t go much beyond, “Hey, isn’t that a neat coincidence” to “what can I do with that coincidence?”  I’ve read some of these stories that are quite good, but the bulk of them just fall flat.
 

IX. Thou Shalt Mingle Thy Mythologies Sparingly

Our story opens in Cascade, Washington.  Duncan MacLeod (or Methos, or Richie) is in town for some reason or another, and just happens to run into one Blair Sandburg.  Naturally, they hit it off, and Blair introduces Duncan/Methos/Richie to his roommate, friend, and partner, Jim Ellison.

Now, everyone who doesn’t know that Blair, or Jim, or both will turn out to be immortal by the end of the story, raise your hand.

Again, there is nothing inherently wrong with this set-up, if used sparingly.  The odds of Jim and Blair both being immortal seem a little long to me – even over the course of the series, immortals were extremely rare, maybe one or two in a large city.  I can stretch my disbelief far enough that both were adopted and didn’t know it (it fits their respective backgrounds – Naomi could have picked up a kid in her travels, and William Ellison seems fond of secrets).  So I can stretch…but it helps if the writer knows it’s a stretch.  Peter David counsels writers to have a character voice how improbable something is (89).  That’s not bad advice, and it takes some of the sting out of stretching disbelief quite so far.

Where I run into problems is when the writer either stretches probability without acknowledging that they’re doing so, or stretches it even further by having (you guessed it) Simon be an immortal (see Commandment VIII about same-actor crossovers).  Or turn Duncan into a sentinel.  Or have Blair, Jim, and Benton Frasier (who is, of course, a Sentinel) also be immortal.  And they all run into Iolaus, who’s alive, of course because he’s…you get the idea.  Besides, Mulder’s got plenty of weirdness going for him already.

Immortals, sentinels, vampires: these things all have a cool factor that makes us want to spread them around.  The idea that Blair, who is usually the youngest person in any given TS ep, could actually be a few hundred years old, is undeniably nifty.  But in our desire to spread them around, we forget that part of the cool factor is in their rareness.  If everyone in the story is immortal or a sentinel, that cool is diminished.
 

X. Thou Shalt Leave Long-Lost Relatives Lost

If there’s any crossover more common than the “Daniel and Blair were lovers in college and now they’ve met again” theme, it’s the “Walter Skinner is Blair’s father” story.  Actually, I’ve only seen one where he was Blair’s father, but that image made a later story in which he and Blair are lovers … interesting.

Blair has had any number of crossover fathers: Starsky (Candy Apple), Ray Doyle/Alan Cade (Brenda Antrim),  MacGyver (Cindy Combs), Magnum (Alyjude, see Commandment II), Skinner (Brandy),  Vincent of Beauty and the Beast (saraid),  Control(Tae), and Joe Dawson (Mona Ramsey).

Meanwhile, Jim has encountered his long lost twin/half-brother Mack Wolfe (of One West Waikiki) any number of times.

Between Blair’s unknown father and Richard Burgi’s other series, the Sentinel has been beset with long lost relatives from other shows.  Meanwhile, Jack O’Neill has been visited by his brother MacGyver (who naturally falls for Daniel – see Commandment VII).

Now, I’ll confess to a weakness for Blair’s father stories.  Probably has something to do with being an adoptee who’s unsuccessfully looked for her birthparents.  So as a well-written story, I rather like Blair’s father crossovers.  The problem is that so many of them take us straight to Commandment I: they’re stories built on a gimmick rather than stories that solidly work the crossover into a good plot and/or good character development.

Of all the Blair’s father stories I’ve read, I think Candy Apple’s S&H crossover “Outside Influences” works the best.  Although it falls prey to Commandment VII, Candy deals thoroughly with the implications of Starsky being Blair’s father.  Besides actually having them take a DNA test, she gives a solid reason for Naomi never telling Blair who his father was (contrast this with Brenda Antrim’s flaky Naomi who just never thought to say anything, or Alyjude’s complete non-explanation, or the several “I thought he was dead” explanations).

Moreover, she weaves the plot of this discovery into a compelling case plot, using it to further both the case and Jim and Blair’s relationship.  In contrast, the discovery that Magnum is Blair’s father in Homeward Bound seems utterly unconnected to everything else going on in the story, and indeed is a distraction from the larger plot.

The real problem with long-lost relatives is that they break Commandments I and V.  Unless the writer is willing to do the work to reconcile any contradictions, and unless the discovery is part of the larger plot, or works to further plot and character development, it comes across as little more than a cheap gimmick.
 

I planned to end this column with the caveat that a good writer can get around just about any of these, but on reflection, I’m not entirely sure that’s true.  Don’t get me wrong: Brenda Antrim has made me believe any number of improbable things.  But other, equally strong writers have written crossovers that made me wonder just what the heck they were thinking.

So instead I will say that most of these commandments stand as cautions rather than absolutes, things that even the strongest of writers should approach with some restraint.  Crossovers are among the most tempting stories in fandom, but they’re also the most difficult.