Crossovers are a funny thing; as I alluded to earlier in the week, most early crossovers were between popular shows on the same network that weren’t necessarily meant to be in continuity with each other when they were created. That’s how we end up with things like Adam West’s Batman and the original Green Hornet in the same universe. This tends to have some strange consequences, where previous in-jokes (like Batman watching Green Hornet on TV) no longer make sense or cause outright contradictions when trying to combine the two continuities. And while a main character crossing over is by far the easiest, most obvious, and hardest to deny of all the crossover types, there are many, many other ways for two shows to imply that they coexist in the same universe–some of which don’t even necessarily require permission from one of the shows! And that’s how we end up with these, some of the weirdest crossovers seen on TV.

4. X-Files meets Detective John Munch

Immediately after letting them go, he makes a tin foil hat quip. If only he knew, eh?

Detective John Munch is kind of a legend, if you’re at all interested in the concept of TV crossovers. Having started out on a police procedural called Homicide: Life on the Street, which was set in Baltimore and considered to be particularly grim and realistic for its time, he has since moved on to Law & Order: SVU and appeared on a million other shows. But looking over the shows that this character has appeared on, well, “one of these things is not like the other” (and it’s not Sesame Street, although he’s been there, too). See, in the episode “Unusual Suspects,” Munch has captured and is in the process of interrogating “The Lone Gunmen,” a group of conspiracy theorists who are friends of Mulder’s. They tell Munch a crazy tale about a government conspiracy to test a mind-altering gas on the population of Baltimore, which was (sort of) stopped by Mulder and the Lone Gunmen. Munch thinks they’re full of shit, but Mulder vouches for them, and they’re allowed to go.

Funny thing is, in his home series, Munch is occasionally referred to as a conspiracy theorist himself. But then, if his world is in continuity with that of The X-Files, he seems to be pretty damn justified. One wonders just how many unsolved cases from Homicide or Law & Order ended up going unsolved because of some kind of paranormal or alien intervention that the characters of those shows were completely unaware of.

Of course, this has some problems with it; there are instances of characters, and even Munch specifically, referring to Mulder and Scully as if they are fictional. It’s not impossible to reconcile (possibly in a “we made a TV show as a cover” sort of way, just like in Stargate SG-1), but it’s enough doubt for most people to let it go.

3. The Peculiar Case of Ba”bear”lon 5

Uh oh. Sheridan’s getting crazy eyes again.

This is a pretty silly one, admittedly, that came about as a result of J. Michael Straczynski‘s (JMS for short) hatred of merchandising and all things cute. He hated the idea so much that he incorporated the idea of merchandising the Babylon 5 station in-universe, much to Sheridan’s annoyance. Eventually, main character John Sheridan spots a bear Ivanova is holding that has on a shirt which reads “Babearlon 5” on the back and “J.S.” on the front. This is apparently the last straw, as he flips out, tossing the bear out the airlock and into deep space. And that’s the end of merchandising on his space station.

In realitysville, the bear was a gift by show writer Peter David’s wife for JMS. JMS changed the ending of the merchandise episode (which Peter David had actually written) specifically to do this. Seems a little harsh and uncalled for; I mean, it’s the thought that counts, right? David found it too mean, too, so he devised a convoluted revenge plan of his own. See, Peter David had his own show, Space Cases, which was really a kid’s show about a crew of cadets lost in deep space (one of whom was a young, pre-Firefly Jewel Staite). So David got the bear back and worked it into a plot on HIS show–the characters find this same teddy bear (minus the shirt), which has been floating around aimlessly for who knows how long. They eventually discover that the bear is a trap, set up by evil aliens, “the Straczyn,” who were trying to conquer the universe on a tight budget. Think the aliens who spiffed up V’Ger from Star Trek: The Motion Picture, except instead of a Voyager probe, it’s a teddy bear. At this rate, I half expect to see it in JMS’s upcoming Netflix series, Sense8, hurtling down through Earth’s atmosphere after smacking into one of those Planet of the Apes-style time warps. I found both scenes together here, if you’d like to see for yourself.

2. Doctor Who: Dimensions in Time

The Third Doctor in Albert Square. Damn shame this mess was his last appearance.

You are the BBC. How do you celebrate the 30th anniversary of a show you unceremoniously canceled 4 years earlier? With a nonsensical crossover, of course! Filmed entirely on the set of the British soap opera EastEnders, this special features the Doctor and his companions randomly changing without warning as a result of the Rani (another Time Lord) interfering with the Doctor’s timeline. They jump around time, going as far back as 1973 and as far forward as 2013, interacting with the various members of the EastEnders cast and trying to figure out what the fuck is happening. Finally the madness literally becomes too much and breaks the Rani’s machine, allowing everyone to escape this fever dream from hell.

It was shot for the “Children in Need” charity, the same one that many of the Doctor Who mini-episodes are still filmed for today. Fortunately the quality has gone up quite a bit in the years since, although I imagine having standing sets available helps. Everyone involved worked for free, under the stipulation that it never be aired again or sold for profit, which means it’s relegated to poor quality VHS-ripped youtube videos these days. In the time since, both EastEnders and Doctor Who have made it clear that they are mutually fictional to one another, so we can just safely toss this out and not even bother trying to make sense of it.

It’s kind of funny that they ended up using a similar premise (a villain manipulating the Doctor’s timeline) in “Name of the Doctor” to prepare for the 50th anniversary. I can imagine some classic Who fans flipping out in fear that this would somehow canonize DiT.

1. Star Trek meets Knight Rider, against all reason

This is a picture of Nomad because I really didn’t want to have to dig up Team Knight Rider.

This is it, the crossover I promised you on Monday. This thing is practically an abomination, and the mess it brings with it would cause fan headaches to no end if anyone took it seriously. So how did this happen without someone putting a stop to it? It’s just so damn indirect that no one would catch on until it was far too late.

See, in the original Star Trek, there’s an episode called “The Changeling,” where the Enterprise finds a long lost probe called Nomad, who really hates humans for some reason and mistakes Kirk for its creator. This is good for the crew, because it will listen to Kirk for long enough to stop harassing them. But as they discover, its creator is actually a guy named Jackson Roykirk, which Nomad has remembered improperly as James Kirk. Kirk uses his +3 to techbane to convince Nomad of its mistake and cause it to self destruct, as he so often did with crazed AI. Problem solved, see you next week!

Well… then there’s this episode of Team Knight Rider, a 90’s spinoff of Knight Rider. On that show, there’s a character Kevin Sanders. And in this one episode, he decides to infiltrate a televangelist operation who appear to be using an earthquake machine to give off the appearance of divine intervention. Sanders is pissed cause he kinda built the thing and he doesn’t like it being used in this way. How did the televangelist get it? From the lead scientist of the project, one Dr. Jackson Roykirk. So? Name’s the same, happens sometimes. But it’s not just the same name–he mentions working on a space probe, Nomad. And with Nomad launched in the early 21st century (sometimes said to be 2002, other times 2020, but never so specific in canon) the timeline matches up pretty well.

It gets worse, as the character of Sanders is better known by his nickname, “Trek.” A nickname given to him by his parents, who are huge Star Trek fans. Yeah. This is how Memory Alpha justifies ignoring the connection, and I think it’s for the best if we all just go along with that, huh?

If you enjoy reading about these headache-inducing crossovers, there are tons more outside the sci-fi genre you can find here. The site’s… a bit dated, to say the least, but it’s still without a doubt one of the most elaborate TV crossover catalogs online.