The good old Involuntary Group Split. Normally PCs will do anything in their power to avoid splitting the party. At least the genre-savvy ones will. Which is a good thing because GMing a split party can be a nightmare. But sometimes you want to split them up fo some reason - to remove party members who could too easily solve a problem, or to heighten drama and tension. And when you need to, there are plenty of ways to do it. An intervening door is probably actually the least creative.

Transcript

GM: R2, make a roll.
R2-D2: Awesome. Hacking? Electronic Countermeasures?
GM: Dexterity.
R2-D2: Crap crap.
[SFX]: < eedoo-poppy-poppy >
{Door comes down, separating R2 and Luke}
R2-D2: Dammit, this whole place is gritching out. I programmed the doors not to close on us.
[SFX]: < fibedooby prow doodle doop bleep boodit-ting-pow boop boodit >
R2-D2: Laser sword the door open.
[SFX]: < whroop whirdle boodit-ting-pow >
Luke: Can't you hack it?
R2-D2: Of course I can! Stand back.
[SFX]: < doop di-dit squee dooboot >
GM: You see an intriguing room ahead.
Luke: Hang on, R2. I'll just check this out.
R2-D2: Don't split the party!
[SFX]: < squee boop whirdle doosquee >
Luke: Yeah, I think it's a bit late for that now.