By the Pricking of My Thumbs By the Pricking of My Thumbs By The Pricking of My Thumbs is a work of detective fiction by Agatha Christie and first published in the UK by the Collins Crime Club in November 1968 and in the US by Dodd, Mead and Company later in the same year. The UK edition retailed at twenty-one shillings (21/-) and the US edition at $4.95. It features her detectives Tommy and Tuppence Beresford. Tommy and Tuppence were unusual in that they aged from novel to novel unlike Miss Marple and Hercule Poirot, whose age remained more or less the same from Christie's
Partners in Crime (short story collection) can take on cases as this detective agency, an opportunity that delights the young couple. They employ Albert, a young man also introduced in "The Secret Adversary", as their assistant at the agency. The two tackle a series of cases – mimicking in each the style of a famous fictional detective of the period, including Sherlock Holmes and Christie's own Hercule Poirot. At the end of the book, Tuppence reveals that she is pregnant, and will play a diminished role in the spy business. Prudence ("Tuppence") Beresford, who is happily married to Tommy for six years, is bored with life.