In media res meme

In media res
(Latin: "in the midst of things")
the practice of beginning an epic or other narrative by plunging
into a crucial situation that is part of a related chain of events.
How to play:

• The action has already begun! No blank top-levels, and something must be happening, whether it's a bar fight or your character's meticulously-constructed house of cards being knocked over by a gust of wind. ETA: Top level comments should contain a starter scenario! Sorry if I wasn't clear enough about that.
• It's okay to assume characters have already been introduced--if by "introduced" you mean "plowed into while on the run from the zombie horde."
• List your preferences, and respect other people's.
• Glance over some ideas to get you started, or RNG if you wanna:

01 Chase Scene: On the run from the cops, or maybe you are the cops. However it works, someone's trying to get away, and someone else doesn't want 'em to. Also good for zombies, dinosaurs, and disaster movies.

02 Gambling: Strangers of all stripes can run into each other at the roulette wheel or poker table, whether it's a classy casino in Monaco or an illegal dice game in a Gotham alleyway.

03 A Formal Affair: Maybe it's an elegant dinner or maybe it's an over-the-top post-Oscar bash, but you're at a party where no expense was spared. Obviously someone is going to start a scene. Maybe it's you.

04 An Informal Affair: Not all parties feature red carpets or the family silver. Sometimes you just want to hang out with friends. Sometimes that's not as easy as it sounds. Maybe the barbecue grill's on fire. Maybe the host is. Whatever--this is not as relaxing as planned.

05 In Flagrante: This isn't what you think! Or maybe it is. Either way, someone got busted, and it looks bad. This doesn't have to be NSFW; there are lots of embarrassing things you can get caught doing with your pants on.

06 Lost: I thought you printed the directions! Unfamiliar city or middle of nowhere, you are lost. Maybe the other character's lost with you, or maybe they can give you some guidance.

07 Fight Scene: Bars, battles, barbarians--the punches or bullets are flying, and you're in the middle of it. Will you escape with your roguish good looks intact? Will you escape at all?

08 Handcuffed Together: Some prompts are evergreen, okay.

09 Roll Your Own: Ice skating rink, pirates, picnic lunch raided by giant radioactive ants...I can't think of everything.