Unruly police detective DCI Charlie Hicks is deeply suspicious of his new partner DI Elaine Renko. But their first investigation exposes a secret that will connect them for life.

A murderer confesses to a priest that he wants to challenge God into revealing Himself by targeting those who help others. Grace makes Hicks an offer.

An internet killer is targeting people who believe they wish to die and Mooney thinks he knows how to trap him. Renko and Hicks change tactic and bring the fight to Grace's door.