In the city of Saint Canard, the villains Quackerjack, Megavolt, and The Liquidator set off a bomb in order to rob a bank. As they are fleeing, the nearby streetlights are inexplicably smashed, and purple smoke begins to roll in. The culprit of both unexpected effects is none other than Darkwing Duck, who pursues the fleeing villains and soon confronts them. It is then revealed that this is taking place in an episode of the Darkwing Duck show, which Dewey is watching at Launchpad's garage.
With Dewey being unaware of the show, Launchpad explains the nature of the series and its star, Jim Starling, to Dewey as he is getting together an outfit trying to look his best. Once finished, he and Dewey get into Scrooge's limo, and Launchpad reveals that he is celebrating finally receiving his driver's license. The two then travel to the Money Bin, where Launchpad is expecting a party after having mailed his license to Scrooge to share the good news. However, no such celebration is forthcoming, and the pair find Scrooge with Gyro Gearloose in the latter's lab.
Scrooge is witnessing a presentation of Gyro's latest concept when the demonstration is wrecked by Gyro's new intern, Fenton Crackshell-Cabrera. In the midst of dealing with the mess, Dewey reveals that Mark Beaks has introduced an uncrashable, self-driving car. Gyro and Scrooge immediately head off to investigate, but not before Scrooge tosses Launchpad the unopened envelope containing his driver's license, having not even checked inside. All four then make their way to the exhibition of B.U.D.D.Y., Beaks' robotic driver. Scrooge is quickly impressed and expresses interest in obtaining a fleet of the automatons.
Feeling threatened, Launchpad challenges B.U.D.D.Y. to a race, and then sneaks into Gyro's lab with Dewey later than night looking for a way to ensure his victory. The pair are apprehended by Manny, now working as another of Gyro's interns, and end up conferencing with Fenton who offers to help. At the race, Fenton implements a complicated method in hopes of aiding Launchpad, but it does more harm than good. Despite utilizing multiple different vehicles in an effort to defeat B.U.D.D.Y., Launchpad loses the race.
Gyro, who was spying on the race, emerges and reveals that he has learned where the technology for B.U.D.D.Y. came from: it's based on his own Bulb Tech. To his fury, he learns that Fenton posted Lil Bulb's blueprints online while looking for help preventing Lil Bulb from turning evil again, and Gyro promptly fires Fenton. The despondent ex-intern then joins an equally depressed Launchpad while Gyro, Scrooge, Dewey, and Beaks climb into B.U.D.D.Y.'s car. However, he quickly discovers that Beaks' modifications to B.U.D.D.Y. were mostly cosmetic, and the robot turns evil and takes the four hostages.
Recognizing the plight of their employers and friends, Launchpad and Fenton launch into action, with Launchpad using Scrooge's limo to pursue them while Fenton activates an invention of Gyro's that he attempted to show off earlier. The device, a set of robotic armor, assembles around Fenton and transforms him into Gizmoduck, who puts his suit to use in an effort to rescue B.U.D.D.Y.'s hostages. While he succeeds in doing so, his inexperience with the suit leaves him at B.U.D.D.Y.'s mercy, and Launchpad and Dewey come to his aid.
After a tense confrontation on the road-during which Launchpad and Dewey learn that Fenton is using the suit-B.U.D.D.Y. is knocked off a cliff into a river. Back at the Money Bin, Scrooge acknowledges Launchpad's receipt of his license and also his appreciation for his driver/pilot. Fenton attempts to claim that the Gizmoduck suit disappeared, but Gyro dismisses his fabrications and reverses his decision to fire Fenton. Unbeknownst to them, Mark Beaks is now determined to claim Gizmoduck for himself.
The Ratcatcher is briefly seen in the background as Darkwing Duck's vehicle.
According to Launchpad's driver's license, his birthday is September 18th, but in the original series episode "A DuckTales Valentine", he said he was an Aries, which would mean his birthday is between March 21st and April 19th. This is presumably a difference in canon between the two series, and reflects the airdate of the original DuckTales cartoon.