The story opens in a blazing, energetic New York City, where theatrical rehearsals are in full swing as September approaches. Kitty Legaye, an actress who jealously guards the illusion of her youth, invites struggling ingenué Sybil Merivale to lunch. During their meal, they encounter the brooding, magnetic actor Alan Mortimer and the producing manager Max Dukane, alongside a detective named Jim Barrison who is advising the company on finger-print scenes. Mortimer, having dismissed his leading woman Grace Templeton, impulsively casts Sybil in the lead role, sparking immediate jealousy, suspicion, and a deep-seated dread within the young actress.
As rehearsals progress behind the scenes at the Mirror Theater, the atmosphere becomes increasingly charged with tension and unvoiced hatred. Mortimer’s volatile temperament, combined with his disturbing infatuation with Sybil and the bitter resentment of the discarded Templeton, creates a volatile emotional triangle. Sinister warning letters begin to arrive for Mortimer, predicting a violent reckoning on opening night.
Despite these ominous portents and the strange, psychic premonitions haunting Sybil, the production presses forward toward its high-stakes premiere. On the opening night of 'Boots and Saddles,' the oppressive summer heat mirrors the mounting psychological pressure backstage. Jim Barrison moves between the front of the house and the wings, remaining watchful despite his initial skepticism. During a climactic, pitch-dark scene in the final act, amidst the sound of blank shots, a fatal seventh shot rings out.
Mortimer is discovered dead at the foot of the stage steps, killed instantly by a bullet to the chest. An exhaustive police investigation follows under Inspector Lowry, casting suspicion on various members of the company. Sybil’s close proximity to the crime, her revealed confession of having threatened Mortimer, and the discovery of a mysterious jewel pendant complicate her standing.
Meanwhile, old secrets involving Mortimer's shadowy past in a Western daredevil show begin to surface, intertwining with the complex vendettas of the women in his life. The investigation ultimately broadens to uncover deeply buried connections from the past, including the vengeful motivations of Wrenn’s daughter, Marita, who performed as a crack shot. Through careful cross-referencing of handwriting, hidden weapons, and unexpected confessions, the complex web of theatrical rivalries and long-delayed retribution is slowly unraveled by Barrison and the authorities.
