Everyone on This Train Is a Suspect is a wickedly clever locked-room murder mystery by Australian author Benjamin Stevenson, published by HarperCollins. It is the second book in the Ernest Cunningham Mysteries series, following the bestselling Everyone in My Family Has Killed Someone.

Ernest Cunningham, an amateur sleuth and true-crime author, boards the Ghan — a legendary passenger train crossing the Australian outback — to attend a literary festival hosted aboard the train. When a fellow passenger is found dead, Ernest finds himself once again at the center of a murder investigation, surrounded by a cast of mystery writers who should know exactly how to get away with it. The train becomes a sealed setting in classic whodunit tradition, and the killer could be anyone on board.

Packed with wit, self-aware humor, and intricate plotting, the novel is a love letter to the golden age of detective fiction while subverting its conventions at every turn. Praised by critics as "Brilliant" (The Times) and named a Crime Book of the Month, it delivers both a satisfying puzzle and sharp comic writing.