Five years after his friend and mentor's death, Lewis - now promoted to position of inspector - returns to the city of Oxford after working on the British Virgin Islands. Even before he has the chance to get home and settle in, he and his new, vastly younger partner DS Hathaway are called to a crime scene to help investigate the murder of an American college student. It is soon discovered that one of the suspects has had past dealings with the late Inspector Morse.

The murder of an Oxford graduate sees Lewis and Hathaway investigating the crime. The investigation leads to them to some ex students who are hiding a deadly secret.

An ambitious Oxford student is found dead in her hotel room after inviting a reformed computer hacker to speak at the union. Lewis and Hathaway investigate.

All is not what it seems between two married couples who are old friends, as Lewis and Hathaway start to discover when one wife is found hanged.