A shockingly common adaptation for life among the stars, body-snatching is a problem that any would-be explorer needs to consider before setting off. Even if the alien being in question doesn’t set its sights on your body directly, it can still be a serious issue that your ship has to deal with; after all, you wouldn’t want to accidentally facilitate some kind of subversive invasion of another planet, slowly occurring behind the scenes, would you? I mean, could you imagine if the planet’s leadership just suddenly went totally nuts for no apparent reason? Like, if they just started making nonsense declarations and lying about things you’d just seen them say and do with your own eyes. It’d be so obvious that something was seriously wrong, and yet no one seems to notice this suspiciously body snatcher-like agenda…

Oh, sorry. Maybe that just happens sometimes? Either way, here are 4 points to consider when dealing with aliens that can steal the appearance and/or minds of another.

4. Isolate the Problem

An entire prison planet may be a bit overkill, though.

If you even suspect that someone on your ship has been taken over by a foreign presence, you need to seal that puppy up RIGHT NOW. The last thing the galaxy needs is for the problem to spread. It’s not always ea

sy to tell; while some body-snatchers have a hard time holding back their ego, others can do an unsettlingly good impersonation of the one whose body they stole. Things to watch for include sudden and unexplained changes in desires, particularly fixations on reaching populated areas that border on obsession; dietary shifts, especially when their new food of choice is something they shouldn’t be eating at all; and extreme impatience, particularly when it comes to unexpected setbacks.

Temporarily sabotaging your own ship might start to sound like a good idea at this point, but be careful with that line of thinking. It’s exactly the kind of thing your crew might mistake for the actions of someone who’s already been snatched. Depending on how fast you can move, though, you may not have a choice, but assuming you do, take advantage of the isolation that spaceflight provides to get this problem handled before you arrive. On a planet’s surface? Well… lock the doors and hope for the best.

3.Restrain Paranoia

Remember: the one alien that came closest to defeating the Doctor did exactly this.

So we’ve got an infiltrator aboard, and it’s disguised as one of your crew, or passengers, or friends. You’d be right to be cautious and treat everyone with suspicion, but a breakout of total paranoia often works more in the body snatcher’s favor. We need to keep a level head about this, and yet if every person on a large ship finds out, the paranoid WILL win out. Keeping everyone together is smart, because the body snatcher likely can’t do his thing without giving away his identity… well, probably. Non-corporeal entities are always a problem like that. It might be for the best to inform the crew of what’s going on, but not passengers; hopefully, their training and existing forms of trust will help to prevent the spread of paranoia and react in a way that contains the threat, rather than exacerbate it.

This is where strong leadership comes into play (assuming the Captain wasn’t our first victim). Keep the people calm, unified, and just maybe this will all soon be behind us.

2. Study & Identify

Whatever test you come up with, though… be prepared for the results.

At this point, you’ve probably got some solid evidence of the body snatcher being on board. Maybe someone was taken over, but then the intruder jumped into a new body. Perhaps you were even lucky enough to see it while it was between hosts, giving you a better idea of what you’re working with. It’s time to take what you’ve seen and found and apply that towards a solution. Is there a way you can somehow test people to see if they’re “under the influence,” so to speak? Where was the last place you stopped–do they have any native fauna (or flora, given the original) that could be responsible? Is there a chance that this possessor is somehow robotic, or man-made? Functionally speaking, there’s not a huge difference between something like a Life-Model Decoy or a Zygon, and a parasitically-possessed human, after all.

Finding something the snatcher doesn’t like that’s harmless to regular humans is the best way to defeat it, but there are other things to consider. It may or may not be possible to recover the person it’s currently inhabiting, for example. Wouldn’t you feel bad if you flushed Ensign Timmy out the airlock, only to learn when you arrived at Starbase 127 that a simple transporter separation would have saved his life? If everyone is to survive this encounter, it’s very important to take a rational, scientific approach to the problem–because hey, it’s just as likely that someone else finds Ensign Timmy’s body floating through space with the body snatcher intact, and this whole thing starts up again a few hundred (thousand) years later.

1. Expel the Parasite

Of course, you know… not everyone survives snatching.

We know what we’re up against now; it’s simply a matter of executing the plan, right? Whether its weakness is cold temperatures or acid or good old-fashioned fire, our scientific method-based tactics have discovered a weapon to use. If it’s something that won’t harm the innocent, then go ahead–crank the AC and let this ship chill out for a few days. Otherwise, we’ll have to be a bit more judicious. The body snatcher’s intelligence will really come into play here, because a human-level adversary will be much harder to trick than something operating on animal instinct, and may Generic Deity save you if it’s got the upper hand as far as brains go.

Remember, this is your ship, and no one knows it better. Seal doors and vent sections to steer the body snatcher the way you want it to move; when it’s alone, you can spring your trap without worry. Do adequately prepare before your confrontation, though–if it spreads through touch, make it impossible for skin-to-skin contact to take place. If it’s spores, or some sort of liquid or bile, put on a space suit. Radiation? Lead lining won’t weigh you down in zero G.

If all that fails, or you never found a weakness to exploit at all, then you know what you must do. This thing, this horrible creature which robs people of their minds, of their very identity… it can’t be allowed to spread. All life in the universe could be at stake. Set your ship on a crash course for the nearest star, sip on a cup of tea and listen to Beethoven. Because the body snatcher does have one weakness: its will to survive. That’s what drives it to steal, to deprive others of their chance at life. The human capacity for altruistic self-sacrifice can never be defeated by a creature as base and selfish as that.

Hope that helped you deal with your body snatcher problem, and preferably without having to go down with it. Any techniques that you found particularly effective which I didn’t list here? You can let me know in the comments, or on Twitter @RetroPhaseShift. Or, if you’ve got a different problem with look-alikes, try some tips for cloning. The mailing list will be going out this weekend, so to any new fans, it’s not too late to sign up. I’m taking a break from appearances for a while to focus on book 3, but the list will be the best place to find out future events! And, of course, the FREE bonus story just for joining…