This is book 6 of the "Nero Wolfe Continuation" series.

This note does not contain major spoilers for the book.

Wolfe dodges a case investigating threats to the pastor of a super-church (Wolfe having strong feelings about organized religion), and refers them to Fred Durkin.

Who is shortly arrested for shooting the pastor, and looks very likely to be convicted.

Wolfe of course jumps on it, and works to resolve the case, which ends up turning on the history of the main players in the church.