The cop drama stars Messing as a Laura Diamond, a detective working for her ex-husband. McCormack will guest-star as Dr. Andrew Devlin, Laura's former fiance and an arrogant heart surgeon. He becomes the lead suspect in the investigation, led by Laura, of his ex-wife's death.
McCormack recently starred on Broadway in a revival of The Best Man. His stage credits also include The Play What I Wrote and The Music Man. A five-time Golden Globe nominee, he has appeared in the TV series "Full Circle," "Perception" and "The New Adventures of Old Christine," among others.
Messing made her Broadway debut in Outside Mullingar. She has received eight Golden Globe nominations for "Will & Grace" and "The Starter Wife." Her screen work also includes "Smash," "The Wedding Date" and "The Women."