Edgar Wallace, perhaps best known for creating King Kong, wrote dozens of novels. The Green Rust, his twelfth crime novel, is one of three books he published in 1919. It begins at the English home of the severely ill American millionaire, John Millinborn. With him are his best friend, Kitson, and a local doctor, the Dutch van Heerden. He is murdered in the first chapter, having just left his fortune to his niece, Oliva, whom he has never met. Before he dies, he asks Kitson to find and watch over Oliva.

A millionaire is taken suddenly ill, and sensing his mortality, he asks his attorney to do him one last favor-to find and secretly watch over his missing niece, the daughter of his profligate deceased sister. This niece at the appropriate time would become heir to his millions. However, the millionaire is mysteriously murdered, stabbed to death in his sick bed. Oliva Cresswell, the unsuspecting niece, has been a cashier in a large West End store for five years when she meets a Mr. Beale, a self-described wheat merchant, is attacked in her flat and rescued by this Mr. Beale, is offered a job as his confidential secretary, refuses him, is unexplainably sacked and finds herself in need of his offer. The mysteries multiply and deepen as the story proceeds.