A sinister inquiry into skeletal remains found in a forgotten Brighton storm drain takes Grace down a labyrinthine trail through the past.

A series of death notices in the Oxford Mail, each with a cryptic message, provides clues to Endeavour’s final investigation, while Thursday’s past catches up with him.

Architect Mia scrambles to keep a dark secret under wraps, while insurance investigator Shazia harvests people’s memories of a nearby accident scene.

Jamie’s authority is tested when an old rival from Ardsmuir shows up to settle on the Ridge. Claire finds a new way to cope with the trauma of her assault…