Receiving a warning from a mysterious baron after suffering a home invasion, Veronica Speedwell accepts the baron's shelter and teams up with an ill-tempered naturalist when her host is subsequently murdered.

In 1940, Evelyne Redfern, a secretary for Prime Minister Winston Churchill in the cabinet war rooms, uses all of her amateur sleuthing expertise garnered from years of reading mysteries to solve a murder, teaming up with a cagey minister’s aide to expose a traitor in their midst.