Castle and Beckett learn that The Fist of Capitalism is a sculpture worth $50 million—30 of that is in diamonds. Bryan Hayes, the executive director of the museum where it was being housed, is dead and The Fist of Capitalism is gone. Catching this killer will be like finding lots of stolen diamonds in the rough.

The killer struck during a museum gala. Myrna Ramsey, the development director, says the security system had been disabled. Museum worker/budding artist Alyssa Lofters says Bryan Hayes was a lovely man who allowed her to put one of her sculptures in the exhibit. He also feared someone might steal the Fist of Capitalism.

As Castle and Beckett theorize about the crime, Serena Kaye (guest star Kristin Lehman) gives them the 411as to how the thief made his way into the museum. Who is Serena Kaye, you ask? She happens to be a sexy insurance investigator who will be acting as a consultant on the case. Beckett doesn’t like it. Of course, that may be because Serena isn’t hiding her attraction to Castle.

Serena believes the M.O. of the crime fits the one used by Falco, a top art thief in Europe. He’s never been caught, never been photographed. Castle tags along as Serena meets with a secret informant who suggests Falco was in cahoots with the victim, Bryan Hayes. But the sculpture’s co-owner, Joy McHugh, thinks her soon-to-be ex-hubby, Anton, is the thief. Hmm.