Peter Howitt's romcom stars Gwyneth Paltrow as Helen Quilley, a PR executive fired from her job who consequently arrives home early, to find her partner Gerry in bed with Lydia. But in an alternative storyline, where she misses the train that delivered her to that nightmare scenario, she would have arrived home after Lydia had gone.
As the film flits between the two plotlines, demonstrating the impact an apparently trivial incident can have on lives, professional success and the charming James Hammerton come into her life in the first, while in the second, her relationship with Gerry drags on, along with dead-end jobs. Eventually, her life reaches a crucial point, but which storyline prevails?