Gotham iconic character update: Showrunner Bruno Heller reveals that fans can expect a “prenatal Robin” on the Fox drama series, while rumors of Harley Quinn making an appearance this season are unfounded.

“We’re going to do a prenatal origin story for Robin down the line,” Heller tells EW.

Since Bruce Wayne (David Mazouz) is still a young teenager on the series, his youthful eventual partner Robin hasn’t even been born yet. But that doesn’t mean there isn’t a way to tell a story that touches on his character. “There are no MRIs involved,” Heller assures. “There’s an episode coming up where we learn how Robin’s parents got together.”

Monday’s episode introduced assistant district attorney Harvey Dent/Two Face (Nicholas D’Agosto), whose upbeat cheerfulness hides an undercurrent of rage. And still to come this season is a young version of Scarecrow. “This is not a kid being a loony Scarecrow; this is a couple episodes about how that character has evolved—everyone’s character is formed in their childhood to some degree or another,” Heller says. “His father is involved, as is part of the [character’s] mythology.”

Also, young Poison Ivy (Clare Foley), who has only been seen in the show’s pilot so far, will soon make a return.

But one character who was heavily rumored to join the show won’t be on this season—the sexy psychopath Harley Quinn, who is also the Joker’s jester-dressed sidekick. The character was teased at Gotham‘s New York Comic Con panel last month that included director Danny Cannon and a few of the show’s cast members.

“One of the things about the size and scope and ambitious of this production is that—it’s not that there’s lots of chefs in the kitchen, but there’s a lot of people with opinions and views and inside knowledge,” Heller says. “That aspect of the show—which characters to use and when — is a source of constant discussion. And that may well have been an issue that came up and was dropped … We haven’t got Harley Quinn in it. Riddler’s girlfriend is coming up. And Harley Quinn is definitely planned for later on, but so far no.”

Heller’s reasoning for holding back on Quinn should please fans who have taken the stance that Gotham should introduce villains slowly rather than putting too many in the first season. “You can’t just keep pumping these characters into the show in a comic book sort of way, because you get the Super Friends effect—which isn’t a bad effect, but then you have spaceships and need to go underwater and get wacky villains and the rest of it,” he said. “You have to work as a character piece first. First it has to be real.”

Batman’s arch nemesis The Joker will also eventually come into play, with Heller planning to tease the audience with different characters who might possibly turn into the iconic villain.

While it’s easy to second guess the exact number of iconic characters to have on the show—and clearly from what Heller says above, the creative team debates this internally, as well—the showrunner says he’s had a clear game plan from the beginning.