Following a car crash, Detective Michael Britten (Jason Isaacs) returns to work and finds himself in one of two different realities every time he wakes up, one in which his wife Hannah (Allen) has survived the accident and the other in which his son Rex (Minnette) has survived it instead. To differentiate between the two realities, Michael wears a red rubber band in the reality in which his wife is alive, and a green one in the reality in which his son is alive. As a cue to viewers, scenes in the red-banded reality are rendered in warm color tones, while scenes in the green-banded one are rendered in cool color tones.