World War I is at its height, and amateur sleuth Nell Bray is dedicating herself to the suffragette movement.

Her friend Jenny is hard at work at Nantgarrew military hospital, which specialises in Freudian analysis. When Jenny begs Nell to investigate the attempted murder of a patient, Nell heads for Nantgarrew to help.

It is a mysterious place: someone is committing petty acts of sabotage to show their disapproval of Freud’s theories; one soldier keeps a box of grenades and revolvers under his bed; and another is determined to reach Moscow by bicycle.

Nell’s bafflement turns to horror when the would-be assassin’s aim finally turns true. Nantgarrew – devoted to healing – becomes the site of a murder, and Nell Bray is determined to solve it.