Lou Corso--the tough ex-LAPD cop--is back for a new mystery. It is April and Lou is a changed man. He has a new love affair, he's quit drinking, and is trying to repair his relationship with his estranged daughter, Cordelia. Life would seem to be good, very good. Then some no-good men start getting murdered. What might seem like a good thing--wife abusers being systematically killed by a mysterious gunman--focuses attention on Lou and his Mystery Club--the good Samaritans who fund the aid for battered women that saves them from their murderous husbands and gives them new lives. The cops think that someone who is involved in the work is targeting the husbands.Lou's neck is stuck way out there. He is has a slugfest with one irate husband in a shelter's reception area and has to forcibly extract another girl from her psycho boyfriend's apartment. When the girl disappears, Lou must find her before she turns dead and buried in a shallow grave. When events spiral out of control, Lou always finds a way to mete out justice according to his own code and in April Evil, retribution is coming.