A woman showed up at Nero Wolfe's house. She wanted to use it as a hotel where she could stay hidden for several days. Usually she would not be even let in with such strange request, but Archie just had a disagreement with his employer, so he put her in the guest room while Nero Wolfe had his regular sessions with orchids. As soon as the latter came down the woman was sent away. She was found murdered several hours later. Archie Goodwin felt it was practically his fault, so finding a murderer became personal for him. He even managed to get Nero Wolfe involved.
This story has several interesting details missing from a usual mystery of the series. Nero Wolfe does not have a client in the traditional sense, but he has to leave his house to answer the summons from the police. He almost never gets outside, and each time he does it really means he cannot avoid it. Archie Goodwin volunteers to work with the police. Yes, you read it right: the narrator of the series does unthinkable.
I also found the scene with Archie trying to save another woman's life to be very dramatic like something coming out from a thriller as opposed to traditional mystery.
I felt bad about the murdered woman, but somehow the more I learned about her the less I cared. I am not sure if it was intentional as Rex Stout can and does write quite unsympathetic people. As a mystery it is quite good and I was able to figure it out a little time before Nero Wolfe explains it.