You gotta love the tongue-in-cheek humor the show's creators:
A helicopter flies onto the scene to pick up a prisoner casually jogging out into the prison yard. Looks like the Villain's Rent-A-Copter is doing some good business! But who in the world is running this prison? It seems like Blackgate, much like Arkham, has decided to base their security on the honor system. (Which is why Batman should kill people).
Gordon gets the call that there's a prison break by air, which no one seems particularly surprised by. I guess when you live in a city where Batman is an important part of your criminal justice system, you learn to roll with the punches.
The police get mobilized pretty quick, but as usual they're a step behind Batman. He grapples on to the landing gear of the helicopter as it flies past him. This jostles the copter, and the passenger asks “What was that?” to which the pilot replies “Just some turbulence.”
Lesson #1 of being a criminal in Gotham city: It's never just turbulence. Nor is it just the wind, nor rats, nor just your imagination. In fact, if you ever hear anything anywhere, it's probably a man in a bat suit.
Batman is being carried along by the speeding helicopter, then somehow changes his trajectory in mid-air, to wrap his grappling line around a radio tower. The remarkably strong cable quickly causes the helicopter to halt its forward motion, and because this is apparently a rare non-hovering helicopter, it immediately plummets to crash into the side of a building. The escaping convict shakily wonders aloud “What happened!?”
Lesson #2 BATMAN HAPPENED. BATMAN ALWAYS HAPPENED.
Seriously, what the fuck? Did this guy get transferred to Blackgate from an out-of-state prison? He seems to have no clue about what it means to be a criminal in Gotham city.
After a brief rooftop scuffle (wait...didn't they crash into the SIDE of the building!?) Batman has the escaped criminal on the ropes. The criminal shakily asks “Who are you?”
There's no way this guy isn't a transfer.
Meanwhile Harvey Dent and a mysterious woman he seems quite fond of have been waiting for Bruce Wayne to meet them at a restaurant. Fortunately for the Batman, Alfred works hard to help facilitate his double life, and already has Wayne's clothes picked out, his car running, and his meal selected. Then again, maybe it's less about Alfred helping him maintain a double life, and more about Bruce being a pampered rich kid who thinks using a stealth jet to fight street crime is a good way to spend his family's money.
Dinner seems to go quite well, and the mysterious woman—Pam—gives Harvey a long kiss and a good solid grope before excusing herself for the evening. Bruce and Harvey spend a few minutes talking about how serious business marriage is, then Dent passes out right in his chocolate mousse. An ambulance is called, and Dent is rushed to the hospital where the doctors tell Wayne (and the cops) that the Harvey has been poisoned.
Bruce steals the sample of Harvey's blood the doctor is examining. I know batman is ostensibly good at everything, but is he really more qualified than a doctor?
Morrie: Well, of course he is. He's Batman.
...meanwhile, Detective Bullock grills the restaurant workers about their involvement in Dent's poisoning. One of the fellows, wearing a very nice tuxedo, says “Hey, I only wash the dishes!” To which we say “Arrest that guy right now. No way does any restaurant, no matter how fancy, require their dish washer to wear a motherfucking tuxedo. He's lying.”
Vindicating Morrie's previous claim, Batman does indeed isolate the toxin within an hour of getting Dent's blood back to the Batcave. It is derived from the “Wild Thorny Rose,” which to us sounds like a pretty generic name for any rose, but apparently this kind is extinct. Apparently no environmental survey was performed before ground was broken for Stonegate prison. I thought Bruce Wayne was supposed to be a model of an ethical businessman?
Back at the hospital, he's switched back to Bruce Wayne again, and is sitting outside of Dent's room. This seems like a poor use of the Batman's time, but it turns out to be useful to move the story forward, because Pam tries to kiss him for being a good friend to Harvey.
This causes Batman to remember the long kiss and grope she gave Harvey just before he passed out, and he calls on Alfred to look into her background. As it turns out she gives lectures on extinct plantlife, and stars in a commercial for a perfume she created which she calls “deadly.” Honestly, it's god damned shocking the police don't figure this shit out. Isn't the girlfriend supposed to be suspect #1?
Batman does some surveillance on Pam, and nothing seems too out of the ordinary. The way she talks to her roses is a little creepy, but she's a botanist. Everybody knows botanists are fuckin' crazy. Batman apparently recognizes Pam's roses—which look exactly like every rose we've ever seen—as the magic “Wile Thorny Rose.” He makes a run to grab it, but falls into a giant trap door, and is accosted by plant tentacles.
I thought this was a kid's show! How did they get tentacle rape past the censors!?
OH SHIT, PAM WAS POISON IVY!
With Batman safely tentacle'd, Poison Ivy feels free to engage in the traditional villain monologue, about injustice, and revenge, and the immorality of those responsible! Of course, being Poison Ivy, the entire speech sounds like it was copied from Greenpeace's website. How is this for an angry villain?
She kisses Batman with the same poisoned-lips she used on Dent. When he begins to spit to try to rid himself of the poison, she immediately chastises him, saying she would have offered him the antidote had he not hurt her feelings. What the fuck? Why did you poison him in the first god-damned place if you were going to offer the antidote immediately afterward!?
Batman kicks Ivy in the chest, which is a rare and welcome display of women being treated equally in terms of violence. I understand the desire to avoid reinforcing ideas about domestic violence in shows, but it often detracts significantly from the action when a female superhero or supervillain is somehow immune to any physical attack from their male adversaries. With Ivy distracted, Batman is able to escape from her plant's clutches, but he's still poisoned.
He barely manages to avoid Ivy's crossbow attacks, and accidentally sets the entire green house on fire when he pulls a light fixture down while attempting to grapple to safety. He only escapes from the inferno by holding Ivy's precious Wild Thorny Rose hostage in exchange for the antidote. The two crash through the glass wall of the greenhouse, with Ivy cradling the plant like a child, and muttering “my babies, my babies.”
It's disappointing that right after displaying some measure of gender equality by allowing Ivy to actually participate in physical combat, the writers had to resort to reducing the character to a motherhood archetype. I understand that the Poison Ivy character was created in the 60s, so it's somewhat understandable that she would have sexist roots (Get it? Roots?) but every character in the Batman mythos has evolved to remain current. It's possible for her to identify closely with plants without shoving her into one of the four or five roles that would have been acceptable for a female character in the forties.
The episode ends with Ivy in Stonegate, which serves as a nice bookend to the plot, but doesn't really make sense. She's clearly insane, and should be in Arkham. And, in fact, that is where she is always seen from this point onward.