Last season, producers revealed that The Flash's season 4 big bad won't be a speedster, but gave very little in the way of possibilities as to who it might be -- but the seasonfinale may have provided an important clue when Savitar mentioned a "cerebral inhibitor" that was going to play a big role in defeating a foe they hadn't met yet.
When Abra Kadabra was talking to The Flash about his most dangerous foes, he rattled off a number of familiar names, including Zoom and Eobard Thawne...and one less-familiar one (at least to the TV audience): "DeVoe."
Longtime comic book readers would recognize that name: Clifford DeVoe is a longtime Flash and Titans villain better known as The Thinker.
Created in 1943, The Thinker is one of The Flash's earliest villains. Originally a foe to Jay Garrick, DeVoe battled three generations of Flashes before his death in The Flash #134 in 1998. After his death, though, his brain patterns were used to create an AI that went on to become an antihero.
The Thinker was a tech-enhanced villain, utilizing a number of high-tech gadgets along with a group of cronies. The most significant of his toys was his "Thinking Cap," a metal hat that could project mental force. A replica of the Cap was key in bringing his virtual self back from the grave.
Over the years, he eventually joined the Suicide Squad -- something we're of course unlikely to see on TV right away. Both before that -- and then again after, when he fell off the "reformed supervillain" wagon and went fully bad again -- he was a member of the Injustice Society, often serving alongside The Shade, a character who has been seen on The Flash already.
When Damien Darhk, currently a major player on DC's Legends of Tomorrow, was first introduced at the end of Arrow's third season, it was in a similarly-subtle name-drop, followed by a more significant tease in the season finale, so keep your eyes open for the latter.
The Flash airs Tuesday nights at 8 p.m. ET/PT on The CW.