The Soul of Genius

A botanist digging in the botanical gardens unearths something that was never meant to be found: the body of Professor Murray Hawes, recently buried and recently dead. Hawes was an English professor possessed by a single ambition, solving the riddle of Lewis Carroll's poem The Hunting of the Snark, and the case quickly turns into the kind of impossible quest the show loves. Lewis and Hathaway find themselves chasing a murder that appears to have been committed around a literary obsession.

The victim had a rivalry with his brother, a lecturer in Theology and Moral Philosophy, and that family fracture gives the enquiry its first real shape. Then there is Michelle Marber, an amateur detective who is convinced the killer is local medical researcher Alex Falconer, and whose interference the professionals could do without. The academic puzzle and the police work have to share the screen, and the episode keeps both of them moving.

But the poem's famous nonsense is treated with proper seriousness, which is the show's way: it believes its characters' obsessions matter. Hawes died chasing an answer to a riddle, and the episode is quietly sad about how close he came.

Colin Dexter and Rachel Bennette wrote it, and Brian Kelly directed. Nadine Lewington plays the botanist Liv Nash, Alex Jennings is Rev Conor Hawes, James Fleet takes Dr Alex Falconer, Annabel Mullion plays Thea Falconer, Daisy May is Mia Wallace, Oliver Johnstone plays Vincent Vega, Clare Holman takes Dr Hobson and Rebecca Front appears as Chief Superintendent Innocent. Kevin Whately and Laurence Fox anchor it.

The Hunting of the Snark is a gift of a case for this show, a riddle inside a murder inside a university. The episode treats the poem's puzzle with real seriousness while keeping the police work grounded, and the result is dense and satisfying. Some cases are solved with evidence. This one takes a little poetry as well.