The Seven Dials Mystery is a work of detective fiction by Agatha Christie, first published in the UK by William Collins & Sons on 24 January 1929 and in the US by Dodd, Mead and Company later in the same year.

The Secret of Chimneys is a work of detective fiction by British writer Agatha Christie, first published in the UK by The Bodley Head in June 1925 and in the US by Dodd, Mead and Company later in the same year. It introduces the characters of Superintendent Battle and Lady Eileen "Bundle" Brent. The UK edition retailed at seven shillings and sixpence (7/6) and the US edition at $2.00.