When a student from a prestigious all female college is found dead, Will and Geordie must infiltrate the murky world of campus politics and university societies.

Will and Leonard witness a deadly and deliberate hit-and-run in Grantchester. Geordie traces the car to a pair of decidedly dysfunctional brothers caught in a web of lies.

Will asks Ellie out to the cinema. There has been a brutal murder in the projection booth. The Chapmans get a brick through their window, and Keating discovers that someone has been sleeping in the cinema. What is the connection?

A naked student runs through town yelling "The aliens are coming". Keating is going to arrest him, but Will convinces him it's a bit of high spirits. He is found dead in a field the next day.

After a boxing match between Lucas and Matt, the door is locked. Vic and Will break in and find them both unconscious. It looks like a double suicide. Vic knows more than he is letting on. Luke dies and Keating cannot believe who did it.

Geordie and Will discover a woman dead on the green, with her arms extended like a cross, and a wedding ring on her finger. Then they discover she is a nun.