Preview: Bones (4.12): The Double Trouble in the Panhandle | Bones Spoilers & Preview | Tv Zine 

The death of female conjoined twins who worked in the circus is investigated. The investigation leads Brennan and Booth to go undercover as a Canadian knife-throwing act, and also causes Booth to come face-to-face with a clown.
Keywords: bones, booth, brennan, seeley, boreanaz, deschanel, emily, season 4