Castle: To Love and Die in L.A.

Beckett's former mentor Mike Royce is murdered and Montgomery tells her she is too close to the case to be part of the investigation, so she takes her remaining leave and heads to Los Angeles. On the flight over, she is upgraded to first class and seated near Castle, who says that he is going to LA to check on the progress of the latest Nikki Heat film. They arrive at Royce's last known address to be greeted by Gene Simmons of rock band Kiss, and uncover evidence of an arms dealing business