Traitor's Purse by Margery Allingham

In this gripping mystery novel, the protagonist, Albert Campion, finds himself in a precarious situation, waking up in a hospital with no memory of his identity or past. As he struggles to piece together the fragments of his life, he becomes embroiled in a dangerous conspiracy that threatens national security. With time running out, Campion must rely on his instincts and the help of his loyal friends to uncover the truth and thwart a sinister plot, all while grappling with the haunting void of his forgotten past.