England, 1976. Mrs. Creasy is missing and the Avenue is alive with whispers. The neighbors blame her sudden disappearance on the heat wave, but ten-year-olds Grace and Tilly aren’t convinced, and decide to take matters into their own hands.

Spunky, spirited Grace and quiet, thoughtful Tilly go door to door in search of clues. The cul-de-sac starts to give up its secrets, and the amateur detectives uncover more than they ever imagined. A complicated history of deception begins to emerge—everyone on the Avenue has something to hide.

During that sweltering summer, the lives of all the neighbors begin to unravel. The girls come to realize that the lies told to conceal what happened one fateful day about a decade ago are the same ones Mrs. Creasy was starting to peel back just before she disappeared...