Dead to Get Ready--and Go. The Dead Detective Mysteries, #4

Last book of the Dead Detective Mysteries. Uneasy and bored with life on the ship, Seamus decides it's time to do what he's been avoiding for six decades of Earth Time. Though he knows his wife and best friend teamed up to murder him, there are things about the crime he doesn't understand, as well as emotions he hasn't yet been able to face. With fellow Dead Detective Ronnie to assist, Seamus returns to 1953 to face his memories and answer questions that remain about his death.
In a world much different from today, in an America where questions of race and social justice are just beginning to be addressed, the two detectives find lots going on under the surface. Chicago offers opportunities for crime on many levels, and there's always someone around to take advantage of those with secrets. Seamus learns a shocking truth about his wife and the secret she kept from him, one that eventually led to his murder.
In the end he and Ronnie must work to save the lives of two young cops brave enough-maybe foolhardy enough-to try to discover what really happened the night Seamus Hanrahan died.