Last month, Arrow and The Flash executive producer Andrew Kreisberg confirmed an earlier report that a crossover between the two DC Comics series will happen this season, which involves Emily Bett Rickards' Felicity Smoak in the eighth episodes of both shows. However, it seems that another, much different type of crossover will happen one week before this big event, with Robert Knepper reprising his Arrow Season 2 role as William Tockman/The Clock King on Episode 7 of The Flash.
The Clock King is the first villain to face both Oliver Queen (Stephen Amell) and Barry Allen (Grant Gustin), following the character's debut appearance in the Arrow Season 2 episode "Time of Death". Andrew Kreisberg revealed to TV Line that Barry will actually be facing Tockman and another unspecified villain at the same time. Here's what he had to say below.
"We wanted to give Barry a real challenge... TWO bad guys! (Barry will be) fighting both a new enemy and one of our scariest and most successful Arrow villains in The Clock King."