"Welcome to Earth-2" is the thirteenth episode, and first part of a two-part story arc, of the second season of the American television series The Flash, based on the DC Comics character Barry Allen / Flash. It follows a crime scene investigator with super-human speed who fights criminals, including others with superhuman abilities. It is set in the Arrowverse and is a spin-off of Arrow. The episode was written by Katherine Walczak from a story by Greg Berlanti and Andrew Kreisberg, and directed by Millicent Shelton.