Coherence

Eight friends at a dinner party lose phone signal as a comet passes overhead. There is another house up the street with the same eight people in it. Then there are more.

James Ward Byrkit made it for almost nothing over five nights, giving the actors only a daily index card of their character's situation and letting them improvise, so the confusion on screen is partly real.

The film is a controlled unfolding of a many-worlds premise in which the party keeps splitting and the versions start trying to swap themselves into the better timeline.

It is talky, low-fi and genuinely gripping, and it rewards close attention: the glow sticks and the numbered doors are a system you can solve.

The ending is one of the quietest and most disturbing in recent science-fiction horror.