Two Against Scotland Yard

First published in 1931, this novel is the second book in the Mr. Pinkerton mystery series. However, despite the series name, the narrative prominently spotlights Inspector Bull of Scotland Yard, while the shy, timid widower Mr. Evan Pinkerton serves as a supporting character who helps unravel the case.

The story begins with a roadside hold-up in the village of Colnbrook. A gunman stops a car containing an elderly man, George Colton, and his much younger wife, Louise. When Louise attempts to shoot the robber, a firefight breaks out; George is killed, and a satchel containing valuable diamonds belonging to a friend is stolen. Scotland Yard suspects Louise due to an unhappy marriage and a clear motive, but Mr. Pinkerton is convinced she is innocent and sets out to find the real killer.