Eric Tiede

The BAU and local authorities in Los Angeles investigate a series of brutal serial killings that appear to involve a famous comic book artist.

Castle and Beckett suspect a costume-clad vigilante is responsible for the mysterious murder of an ex-con.

Secrets arise when Gibbs' former mother-in-law surfaces as a witness in a murder investigation.

Mysterious cow mutilations and reports of glowing creatures put Nick (David Giuntoli) on a case that forces him to question the existence of aliens within the Wesen world. He also meets a strange UFO expert who seems to know more than he's letting on. Meanwhile, Nick digs further into the key, and Juliette's (Bitsie Tulloch) romantic memories of Nick start coming back in a big way.

Penny (Casey Wilson) tries to change a guy to better suit her tastes, while Brad (Damon Wayans, Jr.) rebels against Jane’s (Eliza Coupe) influence on his life. Meanwhile, Max (Adam Pally) and Alex (Elisha Cuthbert) accuse Dave (Zachary Knighton) of being addicted to V-neck shirts.