One night in his near-empty tower block in contemporary London, screenwriter Adam (Andrew Scott) has a chance encounter with a mysterious neighbor Harry (Paul Mescal), who is the only other occupant of an apartment in the building. Harry, who's also gay, seems to want a relationship, but Adam is reluctant.

While working on a script, Adam is preoccupied with memories of the past and finds himself drawn back to the suburban town where he grew up, and the childhood home where his parents (Claire Foy and Jamie Bell), appear to be living, just as they were on the day they died, 30 years before.