A Gotham police blimp receives a blip while a bat-winged figure flies by. The figure then flies to Phoenix Pharmaceuticals, robs the place, and assaults a guard.
The scene then moves to the City Hall, where it's revealed that Harvey Bullock gave an unauthorized interview with the newspaper, who believed the figure was the Batman, a mysterious costumed vigilante. Bullock requests a tactical squad from Gotham's mayor after being denied by Commissioner Gordon. The Mayor approves the squad, while D.A. Harvey Dent assures Bullock that Batman will be put in jail if he's caught.
At the Batcave, Batman reads the Gotham Glazer and analyzes reports of a series of pharmaceutical robberies while conversing with Alfred. Batman then goes out to investigate Phoenix Labs. Two nightbird scientists see Batman coming in and call the police, who call Bullock and his squad to the labs. However, Commissioner Gordon arrives on the scene to inform Bullock that he has the wrong suspect because another pharmaceutical lab was robbed. Bullock's SWAT team still chases after Batman, but he successfully escapes.
Bruce Wayne then travels to the Gotham Zoo, to meet with chiropterologists (scientists that study bats) Dr. March and Drs. Francine and Kirk Langstrom (Dr. March's daughter and son-in-law), to study a sample of bat fur that Batman found at the scene, as well as a tape of the bat sounds. Batman also analyzes the samples himself at the Batcave, where he can't pinpoint the species of bat that produced the fur and the sound. Dr. March, one of the chiropterologists, calls to say it was made by common brown bats and starlings, but Batman's computer deems this negative. Batman deduces that March was lying and goes to investigate. The scene cuts to a scientist disposing of the evidence.
Dr. Kirk Langstrom is then seen at the Gotham Zoo, apparently trying to suppress something using drugs from Phoenix Labs. Batman then comes in and talks with Langstrom, with him saying that they developed a formula to turn him into a man-bat hybrid. Langstrom took the formula and became addicted to it, even though he wanted to stop. Langstrom then reveals that he, or, "the beast in him" had been trying to make the transformation permanent. Langstrom then transforms into this man-bat hybrid while laughing evilly. Batman uses his grappling hook on Man-Bat, going for a wild flight until Batman manages to subdue him.
Batman then produces an antidote for Langstrom and takes him back to the labs to his wife.
This episode was the first produced of the series, but became the second to be aired. Much later, "Terror in the Sky" becomes a sequel of sorts.
Tropes in this episode include:
- Animation Bump: Noticeable—this episode contains some of the best animation in the series. There's a reason for this: this was the episode made to show what BTAS was capable of, and having the animation be top notch was a big part of that.
- Charles Atlas Superpower: Batman pries an elevator door open with his bare hands.
- Clear My Name: Batman does this due to the city believing he robbed a pharmaceutical company and assaulted a security guard.
- Destination Defenestration: The Man-Bat tosses a security guard out of a window and into the river. Batman even has a talk with Alfred about it.Alfred: You mean it wasn't you tossing guards out of windows last night?
Batman: I only toss butlers, Alfred.
- Early Installment Weirdness: Alfred is voiced by Clive Revill rather than Efram Zimbalist.
- Evil Laugh: Langstrom does this as he transforms into Man-Bat.
- Foreshadowing: Harvey Dent repeatedly flips a coin during the discussion at City Hall.
- Gollum Made Me Do It: Langstrom believes he and Man-Bat are two different people, and Langstrom believes that Man-Bat is trying to make the transformation permanent.
- Jekyll & Hyde: Langstrom is trying to suppress Man-Bat, while Man-Bat is trying to make the transformation permanent.
- Knockout Gas: Batman takes out one group of SWAT officers with gas grenades. They have gas masks, but not the time to put them on before the gas becomes effective.
- Magic Pants: The only article of clothing that remains when Langstrom transforms into Man-Bat.
- One Steve Limit: Averted with Harvey Dent and Harvey Bullock.
- Pin-Pulling Teeth: A S.W.A.T. cop does this with a tear gas grenade.
- Secret Relationship: Two employees at the Phoenix Laboratories are looking for a place to make out when they see Batman sneaking in and call the police.
- Split-Personality Takeover: Man-Bat is trying to dominate Langstrom and transform him permanently into a monster.