When Sarah starts a job in a nursing home, to her surprise she is really good at it. She's a natural with the residents, and begins to form a special bond with Tony, a younger resident who has early onset dementia. The home is chronically underfunded and when the Covid pandemic hits, it suffers from understaffing, sickness and heart-breaking losses.

Detective Inspector Dave Greegan, his partner and the Organized Serial Crime Unit are called in to investigate the suspicious deaths of three London hospital patinents.