The St. Canard museum has a new featured exhibit: the Mystic Eye of Quackzalcoatl, a large and mysterious emerald said to have the power to steal a person's strength. Darkwing appoints himself to guard the jewel, despite the offers of both Launchpad and the guard already posted to the museum to assist him. However, as he boasts of his keen perception, he doesn't notice the Fearsome Five enter through a window and steal the emerald until he walks past its display stand. With minimal effort, he is able to take down Megavolt, Bushroot, and the Liquidator; disgusted at how his partners in crime waste their superpowers, Negaduck leaves with the jewel rather than staying to watch Darkwing also take down Quackerjack. It takes a moment before Darkwing realises that Negaduck has escaped.
With the other members of the Fearsome Five now in a maximum security prison for supervillains, Darkwing plans to get himself arrested and put in the prison to ask the criminals where Negaduck is hiding. In the prison itself, the four villains are on work detail in the prison's vegetable garden; the Liquidator is convinced Negaduck will soon break them out, while Quackerjack seems to be actively enjoying prison life, disturbing his three colleagues. Unfortunately, the Liquidator's confidence is misplaced; at his lair, Negaduck declares he has no plans to break them out, planning to keep the millions the Mystic Eye is worth for himself, while continuing to express how he feels his cohorts' powers are wasted on them, believing he could do so much better if he had them. A dove flies through an open window, and Negaduck tries unsuccessfully to feed it to a stray cat when the Mystic Eye activates, shrinking the dove and transferring its wings to the enlarged cat, which flies out of the window. Realizing that the legends about the Eye's powers were true, Negaduck decides to use the jewel to steal the superpowers of his former partners, meaning he'll be paying them a visit at prison after all.
Darkwing's attempts to get himself arrested as "Demolition Duck" fail as he inadvertently foils a convenience store robbery, earning more press attention and public adoration than he ever receives as Darkwing Duck, but as he jaywalks away from the scene of his "triumph", he is finally caught by the police, and persuades them to send him to the supervillain prison with a display of shadow puppetry. Once in prison, he unsubtly tries to get Megavolt, Bushroot, Quackerjack, and the Liquidator to reveal Negaduck's location; they immediately suspect his true identity and attack him until Bushroot points out that the real Darkwing would have called him insulting names. They proceed to rebuff his further attempts to get information on their leader's whereabouts.
After several failed attempts, Negaduck finally breaks into the prison, sending word to the rest of the Fearsome Five that he will break them out that night. Darkwing overhears Megavolt deliver the news to the Liquidator and rushes to alert Warden Waddlesworth, only to find him tied up by Negaduck. The other criminals' delight quickly gives way to terror as Negaduck uses the Mystic Eye to steal their powers, reducing them to half their normal size and transforming him into the plug-headed, water-legged, vine-armed... jester's hat-wearing chimera Mega-Negaduck, with control over electricity, water, and plant life, and a bit of wackiness thrown in (which Quackerjack is very upset to have lost). After effortlessly besting Darkwing in a one-on-one fight, Mega-Negaduck leaves to wreak havoc in St. Canard, using his former cohorts' powers in ways they never knew were possible.
Megavolt, Bushroot, Quackerjack, and the Liquidator decide to team up with an initially reluctant Darkwing to get their powers back and stop Mega-Negaduck from destroying St. Canard. As Darkwing paddles a raft through the boiling water with which the super-supervillain has flooded the city, it occurs to Bushroot that Negaduck must have absorbed their weaknesses as well as their strengths. Together, they hatch a plan to exploit those weaknesses, tricking Mega-Negaduck into firing electricity at his water-based legs, then leading him into dry cement to immobilise him, and finally taunting him to get him to break down sobbing over their betrayal. As Negaduck falls to the ground, defeated, Darkwing scoops up the Mystic Eye of Quackzalcoatl... and immediately drops it, shattering it and restoring the four supervillains' powers. The newly re-empowered crooks decide to continue the theme of teamwork by teaming up against Darkwing... but Darkwing has also learned a few things about teamwork, and summons Launchpad and Gosalyn in the Thunderquack to drop a net on the four criminals; as he "always" says, everyone needs a little help sometimes.
This episode contains examples of the following tropes:
- Achilles' Heel: Darkwing refers to the plan to defeat the tetra-superpowered Negaduck as "Operation Achilles' Heel", since it involves exploiting the weaknesses he has also absorbed from his erstwhile partners in crime, such as Megavolt's vulnerability to using his electricity while standing in water, or the Liquidator's problems with stepping in cement powder.
- All Your Powers Combined: Negaduck uses the Mystic Eye of Quackzalcoatl to absorb Megavolt's electrical powers, the Liquidator's water-based powers, Bushroot's control of plant life, and Quackerjack's wackiness, allowing him to use all four groups of powers (though he finds Quackerjack's wackiness more irritating than useful).
- Can't Get in Trouble for Nuthin': As part of his ploy to get into the same prison as Megavolt, Bushroot, Quackerjack, and the Liquidator, Darkwing dons a series of ridiculous (and malfunctioning) supervillain costumes. He puts on a pair of rollerskates and a jetpack and calls himself "Rollerduck", but his attempt to snatch a yuppie's briefcase goes awry when the jetpack sends him skyrocketing into the air and then plummeting back to earth. He tries a stereotypical studded leather jacket and mohawk costume and styles himself "Demolition Duck", but when he bursts into a convenience store, the doors fly into two crooks who were already robbing it, allowing the police to collar them (and prompting the police and the press to say how much better "Demolition Duck" is at being a hero than that pathetic Darkwing Duck). Just as Darkwing gives up and walks away from the scene of his accidental triumph, he jaywalks right in front of two policemen, who arrest him immediately.
- Curb-Stomp Battle: After Negaduck transforms into Mega-Negaduck, Darkwing tries firing the gas gun at him, but Negaduck hits the cartridge back at him like a tennis ball, causing him to swallow it and inflate like a balloon. Negaduck then squashes him using the Liquidator's water abilities, leaving him dazed and embedded in the ground.
- Enemy Mine: When Negaduck steals the superpowers of the other members of the Fearsome Five, they team up with Darkwing to defeat their erstwhile leader by exploiting their individual weaknesses, which Negaduck has also absorbed.
- "Eureka!" Moment: As they paddle through the streets on a raft, Darkwing berates the four de-powered supervillains for using the boiling water now flooding St. Canard to make weak tea. His use of the word "weak" sparks a brainwave in Bushroot, who reasons that Negaduck has probably absorbed their weaknesses as well as their strengths, leading the four crooks to advise Darkwing on how to exploit those weaknesses.
- Failed a Spot Check: Darkwing remains oblivious to the fact that the Fearsome Five have broken into the museum to steal the Mystic Eye of Quackzalcoatl, even as he walks past them gathered around the jewel's display stand and mutters, "Hey, how ya doin', guys." When their presence finally sinks in a few seconds later, Darkwing does a massive Double Take.
- Felony Misdemeanor: It isn't until he jaywalks away from the convenience store he accidentally saved from a robbery while trying to commit one of his own that Darkwing finally gets the attention of the police, who arrest him immediately.
- Gag Echo: When Darkwing first dons his "Demolition Duck" costume, he says, "They oughta lock me up just for wearing this ridiculous outfit!" When two policemen arrest him for jaywalking, one of them says, "We oughta lock you up just for wearing this ridiculous outfit!"
- Get into Jail Free: Darkwing is convinced that the other members of the Fearsome Five know where Negaduck is hiding and what his plans are for the Mystic Eye of Quackzalcoatl, so he plans to get himself arrested and sent to the same maximum security supervillain prison in which they have been incarcerated following their defeat at his hands in the museum. It takes a few false starts before he finally gets arrested for jaywalking.
- Growing Wings: Negaduck learns of the Mystic Eye's power when it steals a dove's ability to fly and gives it to a cat, causing it to sprout wings.
- Hoist by His Own Petard: During the battle in the museum in which Darkwing defeats the entire Fearsome Five except Negaduck, he uses Megavolt and Quackerjack's attacks against them.
- When Megavolt fires a bolt of electricity at him, Darkwing ducks out of the way, causing the electricity to bounce off a metal shield immediately behind him and knock Megavolt flying.
- Quackerjack hops onto a stuffed moose and throws a Slinky-like toy at Darkwing, entangling him in the metal coils. But when Darkwing disentangles himself, he throws the ends of the spring over the moose's antlers to form an impromptu slingshot, from which he launches an Egyptian sarcophagus that knocks Quackerjack and the moose into the nearest wall.
- Humiliation Conga: Negaduck is subjected to one of these in the final act. First, Darkwing tricks him into firing a bolt of electricity at his now water-based lower body, short-circuiting him. Next, the other members of the Fearsome Five empty bags of dry cement in his path as he chases after Darkwing, rendering him immobile when he steps in it. Finally, his former allies dance around him mockingly, causing him to both literally and figuratively break down over their betrayal.
- Hypocritical Humor: Megavolt grumbles that Quackerjack seems to have been driven insane by prison life... and immediately begins commiserating with a light bulb.
- Impossibly Tacky Clothes: Darkwing's "Demolition Duck" costume includes a pink mohawk and an over the top studded black leather jacket. He quips that they should "lock [him] up just for wearing this ridiculous outfit!" The police agree, echoing his declaration word for word when they arrest him for jaywalking.
- I Work Alone: Darkwing spends most of the episode insisting that he can get by without help, ignoring Launchpad's repeated offers of assistance and dismissing the guard already stationed at the museum to watch the Mystic Eye of Quackzalcoatl. When Negaduck steals the powers of the other Fearsome Five members, Darkwing is forced to abandon his "I work alone" attitude and team up with the criminals to take down Negaduck, and when they regain their powers, he summons a waiting Launchpad and Gosalyn to stop the newly restored supervillains from teaming up against him.
- Mundane Made Awesome: Upon his arrest, Darkwing is delighted at the prospect of being sent to the supervillain prison, but the policemen who arrest him note that he doesn't seem to have the superpowers required to be classified as a supervillain (a reflection of his Badass Normal status as a superhero). He proceeds to put on a display of shadow puppetry in front of their squad car's headlights and tries to pass it off as an evil superpower; this is good enough for the police, who declare, "Off to the super-pokey with him!" It is less effective when he tries to use more shadow puppetry to ward off an attack from his fellow inmates, three of whom (Megavolt, Bushroot, and the Liquidator) have genuine superpowers.
- No Ontological Inertia: Breaking the Mystic Eye of Quackzalcoatl causes Megavolt, Bushroot, Liquidator and Quackerjack to suddenly regain their powers from Mega Negaduck.
- Officer O'Hara: The two policemen who arrest "Demolition Duck" for jaywalking both have comedy fake Irish accents and slightly whimsical personalities.
- Oh, Crap!: Darkwing gets a very nervous look when the Mystic Eye of Quackzalcoatl shatters and Megavolt, Bushroot, Quackerjack, and the Liquidator have their superpowers restored.
- Paper-Thin Disguise: When Darkwing gets himself arrested as "Demolition Duck" and tries to gain the confidence of Megavolt, Bushroot, Quackerjack, and the Liquidator, he doesn't bother to change his speech patterns, and his alliteration-heavy, egotistical introduction gives him away immediately. Subverted when Bushroot reasons that the real Darkwing Duck would have called him "Bushbrain" or "Melonhead" (Megavolt and Quackerjack decide to use those names for him instead).
- Power Copying: The Mystic Eye of Quackzalcoatl has the power to transfer special abilities from one creature to another. Negaduck first discovers its power when he accidentally transfers a dove's wings onto a cat, and he later uses it to steal the other Fearsome Five members' superpowers, including Megavolt's electrical powers, Bushroot's control of plant life, the Liquidator's control of water, and Quackerjack's wackiness.
- Pre-Asskicking One-Liner: Negaduck sets Megavolt up to deliver a villainous version when Darkwing confronts the Fearsome Five in the museum. However, the asskicking that it is supposed to precede doesn't go as planned when Megavolt's attack is literally reflected back at him.Negaduck: Megavolt! Bushroot! Cash this do-gooder's cheque!
Megavolt: I'm a little low on cash... mind if I charge it!? (fires a bolt of electricity at Darkwing, who ducks out of the way; the electricity bounces off a metal shield behind him and hits Megavolt square in the chest, knocking him backwards out of frame) YAAAAGGH! - Tempting Fate: As Darkwing heads to the museum to begin standing guard over the Mystic Eye of Quackzalcoatl, he tells Launchpad that nothing could possibly go wrong... seconds before he lands in the Ratcatcher with his cape over his face and catapults the bike into the ceiling of his hideout.
- This Is Gonna Suck: After seeing Negaduck become Mega-Negaduck, all Darkwing can say is:"Sometimes it doesn't pay to get out of bed."
- Weaksauce Weakness: One of the Liquidator's weaknesses is cement powder, since it turns his body into wet cement - and then dry cement - on contact. When Negaduck absorbs the Liquidator's control over water, he also absorbs his weakness to cement powder, so his former cohorts empty four bags of it into his path when he is chasing Darkwing during the episode's climax.
- What Kind of Lame Power Is Heart, Anyway?: Lampshaded when a depowered Quackerjack attempts to attack Mega-Negaduck.Quackerjack: I'm ruined! Ruined! Ruined!!!
Mega Negaduck: What are you whining about? You never had any powers to begin with!
Quackerjack: YOU STOLE MY WACKINESS!
Mega Negaduck: I did not- (suddenly sprouts giant teeth similar to Quackerjack's) HOO-HOO HOO HOO! (giant teeth disappear) Okay, so I did! - Why Didn't I Think of That?: After leaving the prison, Negaduck uses Liquidator's powers to part the bay, giving him a clear path to walk to St. Canard. Upon seeing this, Liquidator wonders why he didn't do anything like that himself.
