David Mazouz plays 15-year-old Bruce Wayne. In “Gotham” Season 3, the temple Shaman will be trying to help his character unlock the full potential of his mind. Fox

Everybody knows that the young Bruce Wayne (David Mazouz) in “Gotham” will eventually become Batman, but when exactly this will happen still remains a big question.

According to Mazouz, his character’s transformation into the masked vigilante will take place when he starts to physically look like Batman.

“We’re in Season 3 right now, and I’m fifteen. So I think it just depends on what I look like,” he told Assignment X. “If I’m twenty and I still look like I’m fifteen, then I don’t necessarily have to throw on the cape, but if I’m seventeen and I look like I’m twenty-five – I think it really just depends on what my growth process is and when I start to look like Batman.”

For now, the acting challenge faced by Mazouz is playing two different characters — Bruce and his doppelgänger. “They have completely different personalities. That is for sure,” he said. “I don’t want to give [too much] away, but they do have something in them that’s the same. But it kind of is like playing two completely different characters. I’ll leave it at that right now.”

Bruce isn’t the only one who has a doppelgänger this season. Ed Nygma (Cory Michael Smith) came face-to-face with the living embodiment of his former flame, Kris Kringle (Chelsea Spack) — Isabella (also played by Spack).

Isabella might be one of Hugo Strange's experiments, suspects Bustle. It's possible he resurrected Kristen from the dead and made her think she's Isabella. But to what end, fans still do not know.

On the other hand, 2 Paragraphs suspects that Isabella is actually a Russian assassin named Isabella Cheranova, also known as Echo. In the comic books, Echo had a device implanted in her head which allowed her to telepathically read the thoughts of people and computers.

“Gotham” airs every Monday at 8 p.m. ET on Fox.