David and Molly Jones live with their three-year-old son Michael on Manhattan's Upper West Side. David works at a prestigious New York literary agency. Molly is a freelance copyeditor. They are devoted to their son and secure in their love for each other.

Then Deirdre Grocci invades their lives.

Once upon a time, she was David's wife. Their relationship was marked by kinky, violent sex and Deirdre's unsettling mood swings. That was over five years ago. David hasn't thought much about his ex since then.

But his ex has been thinking about him...

Leaving a trail of shocking violence behind her, she has moved across the country just to be near David again. Soon, she has moved into the Joneses' apartment building. Made friends with Michael. And begun to convince Molly that she is losing her mind.

Most dangerous of all, she lures David back into a world of addictive sex he both craves and fears.

Deirdre won't be content to be the other woman forever. She wants David back. This time, for keeps. But there's one force she didn't reckon on: David's wife. To hold on to her family, her sanity, and her life. Molly is willing to go to hell and back.

Played out against the teeming backdrop of modern urban life-with all its hidden perils and sudden, random violence-THE EX grabs you and doesn't let go until the explosive climax. With this novel, John Lutz proves once again that he is the undisputed master of spine-tingling, edge-of-your-chair suspense.