The Batman (Season 5, Episode 4) - White Heat

Firefly has been planning a luxurious retirement with his girlfriend, Blaze, by stealing the gold stock from Gotham Bank. His girlfriend, who is a brilliant scientist, performs some upgrades to firefly’s suit to aid him in the heist. But when firefly accidentally gets exposed to radioactive phosphorous, he becomes a living nuclear bomb; threatening the very existence of Gotham City. Now the job of Batman is simple; contain firefly before he takes down the whole Gotham City. But can he?
 

Click here to watch the rest of the episodes