After the firm’s senior partner Abel Horniman dies, a large deed box in his office is opened to reveal a corpse.

Bohun has a condition (called in the novel 'parainsomnia') that means he needs less than two hours sleep a night, giving him a great deal of time to help with the investigations.

Suspicion falls initially on the recently-deceased partner, the theory being that Smallbone had been killed to prevent him from publicly denouncing Horniman’s misuse of the Trust funds.

On the book's first appearance, Margery H Oates of the New York Times noted the "tense atmosphere" and called it "a first-rate job".

[4] In the Guardian's 2006 obituary of the author, HRF Keating described the novel as "a classic of the genre ... rich with everyday details of a law practice, both good and naughty, dancing too with pawky humour; at the same time it sets a puzzle to please the most exigent of readers".

[9] In The Story of Classic Crime in 100 Books (2017) Martin Edwards wrote that Michael Gilbert had "exploited his knowledge of life in a solicitors’ practice to witty effect in one of the finest workplace-based detective novels".

[10] Edwards also wrote the introduction to the 2019 British Library reissue in which he said that the book "blends in masterly fashion an authentic setting, pleasingly differentiated characters, smoothly readable prose, and a clever puzzle".