In the Castle episode “G.D.S.,” Castle (Nathan Fillion) goes to Los Angeles to figure out what really happened to him when he was abducted. But he gets roped into a murder case. The Greatest Detective Society (G.D.S.) asks Castle to look into the murder of Philip Harris, a private investigator who was working for a big time Hollywood studio. Castle agrees to investigate but the problem is there’s already a private detective on the case – Kendall Frost.
Detective Kendall Frost is portrayed by Summer Glau. She’s known for her role as River Tam in Joss Whedon’s Firefly
