Maud is convinced something horrible happened to her best friend, Elizabeth, but in her search discovers it may be entwined with another disappearance from her childhood. The answers seem within her grasp, but the onset of dementia keeps pulling them through her fingers.

When her best friend Elizabeth goes missing, Maud (Glenda Jackson) is convinced something terrible has happened. But her search to find Elizabeth unearths an altogether darker unsolved mystery: her sister's disappearance, long buried in the recesses of her memory. Can Maud discover the fate of both missing women before her dementia erases the clues? Based on the novel by Emma Healey.