Firefly tries to upgrade his powers with the aid of his new girlfriend Blaze, but is exposed to radioactive phosphorus and takes on a more dangerous identity as Phosphorus. Now The Bat Team must stop him from using a nuclear power plant to blow up Gotham.
Tropes for this episode include:
- Berserk Button: Firefly has a noticeable one in whenever people fail to get his alias right.
- Bittersweet Ending: Leaning more on the Downer Ending, Batman and co defeat Firefly (now Phosphorus) and save Gotham, but Garfield loses Blaze and is now stuck in his Phosphorus form until the scientists can find a cure for him (if it's even possible now).
- Blessed with Suck: Phosphorus can generate intense heat, far stronger than he ever could as Firefly, but eventually he's unable to interact with anything without melting it or burning it to a crisp.
- "Could Have Avoided This!" Plot: Played With. At the end, one of the doctors at Arkham Asylum explains to Batman that if Firefly/Phosphorus had been brought to them sooner, they might’ve been able to do more about his condition. If Garfield hadn’t been so stubborn and just let Blaze take him to the hospital like she wanted to after the isotope exploded, he probably wouldn’t be in the state he is now.
- Domestic Abuse: After becoming Phosphorus, Garfield's relationship with Blaze devolves into this.
- Failed a Spot Check: During his fight with Phosphorus, a large portion of Batman's mask is burnt off revealing Bruce Wayne's face (or at least enough for him to be recognizable.) No one notices or gives a crap, especially after Phosphorus is subdued.
- Idiot Ball: Firefly decides to work with a radioactive isotope and when he sees a news report get his name wrong, Firefly proceeds to fume about Gotham getting his name wrong, distracting him long enough to destroy the isotope by accident. Additionally, despite having absorbed dangerous radiation from the explosion, he refuses Blaze's insistence on to going to the hospital to avoid getting arrested, and continuously abuses his new powers to commit more crimes and evade capture by the Bat team or the police. This causes both his physical and mental states to steadily deteriorate to the point where he can't even stand anywhere without causing destruction, then loses his mind and tries to destroy the whole city in order to be remembered, and winds up being both stuck in a special cell at Arkham Asylum and dumped by Blaze in the end.
- Irony: As Phosphorus, Firefly is burning hotter than ever before, yet (as Blaze so put it) the "spark" between him and his girlfriend is gone. In addition, his frequent abuse of his new powers and stubborn refusal to get medical help to avoid going back to prison have condemned him to an even worse fate: mutated possibly beyond repair, and stuck in a special cell at Arkham Asylum made to keep his powers in check.
- That Man Is Dead: Upon becoming Phosphorous, Garfield rejects the alias "Firefly".
