This week on Castle, there's dangerous CIA rouge operatives, a doomsday scenario and murder. Most shocking of all, though, is finding out that Beckett wasn't Castle's first muse. That honor goes to the gorgeous Jennifer Beales, playing CIA agent Sophia Turner. Castle based his first books on her and spent a year following her around for "research." We haven't seen Beckett this jealous since Castle's flirtation with sexy Indiana Jones.