A Ghost in the Machine is a crime novel written by English writer Caroline Graham and first published by Headline in 2004.

Unlike the majority of Graham's previous Chief Inspector Barnaby novels, A Ghost in the Machine was not adapted for the television series Midsomer Murders.

[1] Village resident Dennis Brinkley, an enthusiastic collector of old war machines and torture weapons, suffers a gruesome death after being crushed by one of his own devices.

Although his demise is initially regarded as an accident, his best friend Benny believes otherwise, and her suspicions are only confirmed by local psychic Ava Garrett, who tells her that she will ask Dennis to identify his killer at her next seance.

However, the elusive murderer silences her before the event can go ahead, leaving Chief Inspector Barnaby, accompanied by his Sergeant Gavin Troy, with two gruesome slayings and a complex mystery to unravel.