Elliot Langley is a researcher at Lawrence Livermore Labs. Dan contacts Langley in "The Year of the Rabbit" to learn about tachyons, and subsequently speaks with him on the phone in the past. Later in "The Legend of Dylan McCleen", Langley meets with Dan at the Register to further discuss what Dan explains is research for a science fiction novel. In "The Hanged Man", Dan inadvertently changes his own life. Having changed it back by the end of the episode, he meets Langley at the labs, who denies knowing him and has him sent away.