Synopsis of Death of a Doxy
Orrie is finally going to tie the knot. He’s engaged to marry Jill Hardy, a stewardess. But for months, Orrie’s also been keeping company with Isabel Kerr, an ex-showgirl. Orrie has some time available because Jill works international flights. Isabel has time available because she no longer performs: rather, she occupies a plush apartment that’s paid for by another gentleman friend who visits her just two or three times a week.
Isabel objects to Orrie’s marriage plans. She has taken some of his personal and professional belongings and stashed them in her apartment. Isabel threatens to show them to Jill and thus quash the marriage. So, Orrie asks Archie to get into Isabel’s apartment, find his possessions, and get them back. When Archie does enter the apartment, he finds not Orrie’s belongings but Isabel’s body. Archie withdraws to meet with Orrie, but otherwise keeps the news to himself.
Isabel’s sister Stella later discovers the body. The police find Orrie’s possessions in the apartment and arrest him on suspicion of murder. In a meeting to consider whether Orrie is guilty, Wolfe, Archie, and Fred are all unsure, but Saul — via some convoluted reasoning — concludes that he is innocent, and Wolfe undertakes to demonstrate it.
Synopsis taken from https://en.wikipedia.org/wiki/Death_of_a_Doxy