The CW network has released the synopsis for episode #209 of The Flash, which you can check out below. The installment, titled “Running to Stand Still,” is officially described as follows:
MARK HAMILL, WENTWORTH MILLER AND LIAM MCINTYRE RETURN; KEIYNAN LONSDALE JOINS THE CAST AS WALLY WEST — When Mark Mardon AKA The Weather Wizard (guest star Liam McIntyre) returns to break Leonard Snart AKA Captain Cold (guest star Wentworth Miller) and James Jesse AKA The Trickster (guest star Mark Hamill) out of Iron Heights, Barry (Grant Gustin) must stop these rogues from taking over Central City during Christmas. Meanwhile, Joe (Jesse L. Martin) and Iris (Candice Patton) meet Wally West (Keiynan Lonsdale).
The Flash “Running to Stand Still” was directed by Kevin Tancharoen and written by Andrew Kreisberg. The episode airs Tuesday, December 8, at 8pm on The CW.