After responding to a break-in at Stagg Industries, Batman rescues a security guard named Rex Mason who had been exposed to a weaponized toxic gas known as "Project Metamorpho". Soon, Rex begins to mutate and gains the ability to manipulate the elements of his own body. Terrified and unable to control his new abilities, Rex becomes a fugitive. Realizing that this metamorphosis is slowly killing Rex, Batman sets out to find a cure. Rex is only concerned about one thing: Sapphire Stagg (the woman he loves) and he would risk all of Gotham to be with her, but her father Simon Stagg holds secrets of his own and will do anything to keep them apart.
This episode provides examples of:
- Bait the Dog: Stagg genuinely seems to respect Sapphire's decision to be with Rex, even giving him a compliment for being the right pick. In actuality, he absolutely hates the idea of his daughter being in love with a security guard, and tried to separate them by trying to kill Rex.
- Driven to Suicide: Rex tragically attempts this after being turned down by Sapphire by smashing the ventilation system and transforming into a gas, causing himself to be sucked out. It doesn't work; he's shown to be still alive at the end.
- Foreshadowing: How did the intruder know how the Project Metamorpho chamber worked? Because the robber is actually Stagg trying to kill Rex to get him away from his daughter.
- He Knows Too Much: Stagg pretty much tells this to Batman before trying to kill him with two of his security guards, because he knows Batman's hacked into his computer system to prove that Stagg set up Rex for a fall.
- Hypocrite: Stagg.
- For all his claims of respecting Sapphire's decisions, he can't handle the idea of a security guard marrying her.
- Stagg says that if Rex really loved Sapphire, he would've understood that she was bred for better. Rex angrily points out that he didn't even give him a chance.
- After Rex seemingly kills himself, Stagg has the gall to accuse Batman of murdering "a poor heroic man" when he was the one who tried to kill Rex first.
- Lack of Empathy: When Batman points out that the toxic gasses will kill Rex, Stagg nonchalantly replies, "We're still ironing out the kinks."
- Raised Hand of Survival: After seemingly evaporating himself into nothingness, Metamorpho begins to reform himself in the sewer, reaching his hand out of the sewage.
- Super-Soldier: What Project Metamorpho is in a nutshell.
- Written-In Absence: Tatsu's not driving Bruce around today because she's busy shadowing Jason Burr to his new lab after the attack on Wayne Manor.
- You're Insane!: A panicked Stagg calls Batman this for telling Rex the truth and luring him to Stagg Industries to use Stagg as a bait.
