Henry Wilt is a more or less failed teacher who fantasizes about murdering his dominant, non-attentive wife Eva. At a party who gets stuck in an inflatable doll and makes a complete fool of himself. Eventually, he dumps the doll in a hole at a building site. However, he has been witnessed getting rid of the doll and when his wife disappears on the night after the party, the police and Inspector Flint have strong suspicions on Mr Wilt.

In The Clue of the Savant’s Thumb, Creek and fellow investigator Joey Ross (Sheridan Smith – Accused, Gavin & Stacey) are drawn into a complex case involving a secret society, seemingly supernatural events at a girls’ boarding school, and the miraculous disappearance of a body in front of three witnesses. Alan Davies says: “The new story has more than the usual amount of twists and surprises, and I'm very much looking forward to sleuthing again. I can't wait to join Sheridan Smith on set again; we're very lucky to have her. It's nearly 17 years since I first auditioned for the part; the duffle coat is always on standby, even if the periods of duffle-hibernation are quite long these days”.