While investigating the mysterious shooting death of a young woman, Castle and Beckett face a cop's worst nightmare when they discover that the gun used in the killing is Det. Ryan's old service weapon - the one that was stolen by the serial killer, 3XK. Now with the clock ticking, the team must work to solve the murder, track down 3XK and retrieve Ryan's gun before the killer strikes again.
Quest roles:
Ross McCall(Seth Carver), Tim Jo(Ben Lee), Billy Lush(Finn McQueen), Francois Chau(Clifford Lee), Lanny Joon(Philip Lee), Mercedes Colón(Philip Lee's Attorney), Nadine Crocker(Charlotte Rosenberg), Stephanie Nash(Annika Herzfeld), Jessie Graff(Jane Herzfeld), Joe Martin Thomas(Lee Bodyguard), Sam Ayers(Bartender), Michael Yavnielli(Mike Drooen), Allan Wong(Steven Lee)