Cathy's triumph at CeCe's turns dark when a club manager is found dead and Alphy is discovered drunk at an illegal poker game. As Geordie uncovers a web of extortion, friendships fracture and faith falters. Leonard finds hope in caring for young Raymond.

In the aftermath of the CeCe's siege, Geordie fights for his life while fugitive Dex Sutton is on the run. As Alphy and Larry track him through the Cambridgeshire countryside, Alphy's crisis of faith reaches its peak. Meanwhile, Leonard and Daniel take a bold step toward family, and Grantchester must face questions of forgiveness, love, and redemption.