The biggest problem I have with this story is how similar it is to the second story in the book, Big Driver. A woman, when wronged, decides to take justice in her own hands. I would have enjoyed A Good Marriage much more if it had been before Big Driver or if Big Driver would have been in another book.
That being said, A Good Marriage is a good story. Darcellen finds out her husband is secretly a serial killer and then decides to take care of the problem herself. A pesky investigator arrives, understands what Darcellen has done, but lets her go.
Once again, I actually wish that King had taken a different angle with this story. There's a period of time in the story where Darcellen appears to go along with her husband's strange... hobby. I think that actually would have been an interesting angle to run with. A wife who is so desperate to maintain the status quo that she is willing to support her husband as a serial killer.
What's nice about this story is the characterization is so rich. The serial killer comes across as so... normal. He's a coin collector and King connects his chance finding of a very random 1955 double-die penny directly into Darcellen's scheme to kill him. The investator that comes around sniffing for clues after Bob dies is a true Columbo or Matlock - as old as the hills but still mentally sharp. It's touches like this that elevate this story above average.
1LR Review: 16 out of 20 - It's a Hit!