Melissa Benoist's Supergirl was one of several surprise appearances on The Flash tonight.
Preview clip for the Flash episode "Welcome to Earth-2"
Andy Mientus will be returning as the Pied Piper in the Flash episode "Flash Back."
Executive Producers from The Flash preview "Welcome to Earth-2"
Danielle Panabaker has tweeted an awesome photo of Caitlin Snow as Killer Frost.
David Ramsey and Audrey Marie Anderson from Arrow guest star in the Flash episode "King Shark."
Preview images for the Flash episode "Welcome to Earth-2," featuring Robbie Amell, Killer Frost and more
It’s actually happening!!! Grant Gustin will be guest starring on Supergirl in March, playing The Flash (of course). Details acan be found at KryptonSite!
Overnight ratings report for the Flash episode "Fast Lane"
Screen captures from the extended preview trailer for the Flash episode "Welcome to Earth-2"