Thomas Calabro

Former Melrose Place star Thomas Calabro will guest-star on an upcoming episode of Castle.

Check out photos of the Castle cast

Calabro, 51, will play Scott Donner, a client of a Millionaire Matchmaker type who sets up wealthy men with beautiful women, TVGuide.com has learned exclusively. Donner becomes a murder suspect when the matchmaker turns up dead.

The episode also features guest star Laura Prepon. She plays the actress portraying Nikki Heat, the character Castle (Nathan FIllion) based on Beckett (Stana Katic) in Heat Wave, his novel that is being turned into a movie. Prepon will be shadowing Beckett in order to research her character and master Beckett's mannerisms.

Laura Prepon joins Castle as Nikki Heat

Calabro is best known for his role as Dr. Michael Mancini on both the original Melrose Place on Fox and the CW's short-lived reboot of the series last year. He has also recurred on Without a Trace, Nip/Tuck and Greek, and he guest-starred on CSI: NY earlier this season.

His episode, titled "Nikki Heat," is scheduled to air Jan. 3 at 10/9c on ABC.