TVLine has exclusively learned that Simmons will appear as his badass self in Castle‘s Los Angeles-set murder-mystery episode, set to air in early May. Per an ABC insider, Castle (Nathan Fillion) and Beckett (Stana Katic) follow a lead straight to their victim’s Beverly Hills home, which just so happens to be owned by the rock superstar. Turns out, said victim had been living in the pad’s guest house prior to the incident. After a quick chat with Simmons in his fictional Beverly Hills backyard, the crime fighting pair sets off to continue their trek through La-La Land. Craig Ireland 03/04/2011