
Videos by ComicBook.com
That’s because in the teaser trailer for the season finale, which aired last night following “Flash vs. Arrow,” it seems that both men are present in the room when the Reverse-Flash goes after S.T.A.R. Labs.
Update: I’m told the trailer did not air during The Flash in most markets, although it obviously did somewhere, since low-quality images from this teaser appeared online immediately following the episode last night.
What else do we learn about him? Well, he’s in quite a bit of the episode, from the look of things; this shouldn’t just be a simple cameo to whet your appetite in the last thirty seconds, a la last night’s appearance of Firestorm.

You can check them out for different angles and to hunt for clues as to which Reverse-Flash it might be or who could be under the mask.
The Flash airs Tuesday nights at 8 p.m. ET/PT on The CW, but Barry Allen will appear on Arrow tonight at 8 p.m. ET/PT on THe CW.