Before the fourth murder takes place, the team must uncover the guilty secret that their victims share in order to learn the identity of both the killer and the potential victim.

Oxford's last all-female college is holding a reunion party to say goodbye to one of its most popular professors. After a guest is found murdered, Lewis believes the killing is connected to an attack that happened at the same building 10 years ago. He turns to his former DS, Alison McLennan, to help him with the case, but it ends up taking a new twist after two more bodies turn up.

When a classics scholar is stabbed to death and dumped in the Oxford Canal, Lewis, Hathaway and Maddox find themselves sorely tested by a bizarre case.

When College Dean Phil Beskin is found bludgeoned to death with a rock in local woodland, Lewis and Hathaway are called in to investigate.

Lewis investigates when a visiting female bishop is poisoned. Then two more deaths occur, both mirroring macabre murders from Jacobean revenge tragedy.

The ethics of a questionable drug on the Oxford campus of anti-depressants calls into account the questionable judgment of a psychiatry professor.

Lewis and Hathaway are called in to investigate the apparent death by drug overdose of over achieving student and amateur taxidermist Talika Desai.

As Lewis and Hobson embark on a relationship, a former don is murdered on the night of his release from prison - crushed to death by a Jaguar Mark two.

Hathaway has been promoted to Inspector after an extended break from the force, and Lewis is enjoying retired life until he's asked to team up with his old colleague again.

When a babysitter is found dead, Lewis and Hathaway are drawn into diverse new worlds including squats, swinging suburbia, primate labs and fetish photography.

A rape case appears to be solved when the chief suspect is murdered. But nothing is what it seems - and soon the upper echelons of Oxford society close ranks.

Lewis and Hobson are examining the body of murdered Vicki Walmsley when a theft of etorphine is reported by the Garsington Equine Centre. The drug was last used a year earlier on a horse that injured its teenage rider, Joshua Grace – the brother-in-law of Reuben Beatty, the first murder victim.

Lewis comes face to face with his past in a case driven by celebrity, scheming, and dangerous sexual politics.

When Lewis and Hathaway investigate a murder in town, forensic evidence leads them to suspect there is a connection with the reforming of an old rock band.

When the master of a college is found dead at the foot of the observatory stairs, suspicion falls on all of the staff - from senior tutors right down to the scouts.

Lewis and Hathaway investigate when a controversial American academic is murdered after speaking at Oxford's Department of Criminology.

Lewis and Hathaway are thrown into a delicate case involving one of the Oxford University's most prominent figures.

When an Oxford housewife is found hanged in her home, Lewis and Hathaway unearth a far darker murder case than the initial suicide verdict suggests.

Lewis and Hathaway investigate a link between the murder of a professor of German history and the recent winner of a local underground boxing bout.

When an old friend of Hathaway's commits suicide, Lewis investigates a link between his death and a religious group whose members are being targeted by a killer.

When religious fanatic Steven Mullan is murdered, Lewis investigates celebrity atheist Tom Rattenbury and his family, who had been attacked by Mullan.

On a bank holiday weekend Lewis and Hathaway are called in when a top quiz competitor is found floating dead in the fountain of an Oxford college.

Lewis and Hathaway investigate the murder of a university friend of pathologist Laura Hobson. As more deaths occur, they realise that Laura's past may hold the key.

An embalmed body is discovered dumped by an isolated farm track. Funeral director Brian Miller identifies the body and GP Matt Whitby confirms the gentleman died of cancer.

Lewis investigates the murder of a beautiful young Eastern European woman whose death comes straight from the pages of a popular fantasy novel.