Danger is afoot when a group of bored spinsters and lonely widows vows to investigate London's most mysterious crimes. For Augusta Lockwood, who has newly discovered a skeleton under the floor of her house, there are more pressing matters closer to home.

Nonetheless, Augusta cannot refuse a plea for help when one of her society friends believes her life is in peril. To investigate a murder attempt, Augusta must set aside thoughts of her increasingly sinister tenant, Mr. Hawksworth, and the arrival of the troublingly handsome anatomist, Adam Seagrave. She must forget about the mysterious intruder who keeps trying to break into her house, and above all, she must banish thoughts of the dead body in her late father's locked study.

With so much to forget and so little to go on, will Augusta and her friends in the ladies society unmask a fiendish killer before one of their own members becomes the next victim?