Synopsis of Death of a Demon
Lucy Hazen has a preemptive confession to make to Nero Wolfe. Having come to despise her husband Barry, a cruel public relations counsellor, she has recently become plagued by thoughts of shooting him with his own gun. In order to deter herself from following through on this impulse, she has decided to confess this to Nero Wolfe. She knows that if she did commit the crime he would reveal the act to the police. Although bemused by the meeting, Wolfe humors her and agrees to show her his orchid collection, but while they are upstairs Archie Goodwin hears on the radio that Barry Hazen’s body has been discovered in an alley, shot in the back.
Despite Lucy’s confession, Archie is convinced by her reaction when he informs her of her husband’s murder that she is innocent of the crime. Wolfe and Archie learn from Lucy that she last saw her husband at a dinner party held the previous evening for a group of his clients – Mrs. Victor Oliver, Anne Talbot, Jules Khoury and Ambrose Perdis – and his copy-writer Theodore Weed, whom Lucy clearly harbors feelings for.
Although similarly convinced of her innocence, Wolfe is reluctant to accept Lucy as his client and sends her away, though he keeps the gun in his possession for safe-keeping. Using an old mattress, Archie acquires a fired bullet from the gun and turns it over to Inspector Cramer for comparison.
Lucy is detained as a suspect in her husband’s murder, and hires Wolfe to exonerate her.
Synopsis taken from https://en.wikipedia.org/wiki/Death_of_a_Demon