Having recently been pardoned by the British government, the Just Men continue their mission to bring criminals to justice, but now by employing mostly legal means.

London has been terrorized with the death of several men connected with Doktor Oberzohn, the head of an international cartel, with the deaths thought to have been caused by an escaped venomous snake. After forming a detective agency, the Just Men begin working with Scotland Yard to investigate Oberzohn, who is also suspected of having instigated revolts and overthrown governments for profit.

In the course of their investigation, the Just Men become intrigued by the sudden interest Oberzohn has shown in a simple farm girl named Mirabelle Leicester, and her connection with her dead father’s Angolan land claim.