While there have been plenty of hints, teases and even an apparent identity revealed for Batman's baddest foe, Heller says that's all over for the time being -- but only so that they can truly focus on the character's roots come the fall.
"You're not going to see teases of The Joker before the end of the season, because the beginning of Season Two is a big Joker-oriented, or 'how the Joker came to be' kind of story," Heller told ComicBook.com in an interview, the full text of which will run soon. "The beginning of Season Two is the very earliest origins of how The Joker came to be."
Don't expect the character to be all laughing fish and Smilex gas right away, though; Heller described his Joker as "pre-embryonic."
The most popular theory -- and one promoted by FOX -- is that The Joker is a young man named Jerome, who lived his life traveling with the carnival and murdered his mother in an earlier episode of Gotham. That character, played by Cameron Monaghan, was taken away to jail at the end of his sole appearance so far this year.
At WonderCon earlier this year, producers confirmed that Monaghan will return and that fans will get to see "a bit" of Jerome's story in Season Two.
Gotham airs tonight at 8 p.m. ET/PT on FOX.