When the news is announced that a comet is on an unavoidable collision course with Earth, the most hilarious and unexpected chain of events imaginable is set in motion.

2am - Waterloo Bridge, London. When despairing Gracie fails to get up the guts to throw herself off Waterloo Bridge, destiny hands her a chance at salvation when 17 year old Ellie runs up onto the bridge, desperate to escape a man who's hot on her heels. Ellie begs for Gracie's help, and shocked out of her misery, Gracie grabs her and they escape to what Gracie believes, is the safety of the back streets. But those after Ellie do not give up, and so begins a dark, surreal night, during which Gracie realizes she has a chance at redemption and to save Ellie, but only if come morning they can survive the overwhelming odds that face them.

A grief-stricken woman revisits an old seaside haunt where her chance meeting with a teenage boy re-opens channels of communication with the past.