Webby learns how Scrooge and Mrs. Beakley first met while she helps Scrooge rescue her granny from the clutches of rival spy Black Heron.
At McDuck Manor, while Huey, Dewey, and Louie begin to watch an all day marathon of Ottoman Empire, Mrs. Beakley is suddenly ambushed in the kitchen by a cloaked individual with a cybernetic arm. The intruder, addressing Beakley as "Agent 22", greets Beakley who discerns her to be Black Heron, and knocks Beakley out with knockout gas.
The next morning, Scrooge McDuck notices Beakley's absence during breakfast. Webby seizes the opportunity to fill for Beakley's role with Scrooge ignoring the latter's discomfort over the fact that she knows so much about him. When they go to the kitchen, they find it in a disheveled state from Beakley's fight. Webby thinks Donald Duck tried to make an omelette again but Scrooge points out Donald still hasn't figured out how to get out of the pantry. As Scrooge looks around, he finds a single black feather on the floor that he fearfully recognizes. The scene cuts to a flashback in 1960s London. A younger Beakley is Agent 22 of the S.H.U.S.H. agency and assigned to a case to retrieve a page from the Book of Castle Dunwyn before the chemist-turned-F.O.W.L. agent Black Heron does. But since the page is being auctioned at an exclusive high-class event, Director Ludwig Von Drake assigns Beakley with freelance operative Scrooge to attend it. Director Von Drake gives Scrooge an Action Cane P.P.K. equipped with spy gadgets, with Scrooge accidentally activating the knock-out gas feature.
In the present, Scrooge embarks on a mission to rescue Beakley. Scrooge tells the boys he is going on a trip. Webby wants to go but Scrooge refuses to put her in harm's way telling her that Beakley would want to keep her out of trouble. On the way to Black Heron's old hideout, with Launchpad McQuack piloting the sub blindfolded, Scrooge brings out his action cane and accidentally activates a sonic pulse, which shuts off mysteriously. To his dismay, Webby has snuck into the cargo eager to participate in an adventure like Scrooge once had with Beakley. Scrooge reluctantly decides to let Webby tag along since there is no turning back home, and Launchpad is too incompetent to be his partner for this mission.
At the auction, in the past, Scrooge informs Beakley about what was on the page: potion and elixir recipes written by the high priests of Castle Dunwyn, who were mentored by mysterious creatures from a nearby glen with untold powers. They spot Black Heron and try to outbid each other. However, they come to a price Scrooge refuses to pay for, thus Black Heron wins the bid, but Beakley throws a brooch-tracker onto Black Heron before she escapes.
On Black Heron's island, Scrooge and Webby run into Black Heron's security system, a bubble filled with Incindium, where Webby uses the same methods Beakley used in the past to defeat them.
In the past, Scrooge and Agent 22 track Black Heron to an uncharted island and encounter Heron's security measures, which Agent 22 disables by filling the bubble with gas that changes the gas inside bubble from Incindium to helium. They notice mysterious bushes not native to the island. Beakley is flabbergasted that Scrooge ate one of the berries, which weren't poisonous but the latter was choking because a stem got caught in his throat, which he coughs up.
In the present, Scrooge and Webby, the latter of whom could not contain her excitement, enter a hallway full of traps with Webby shouting a battlecry.
Four robot guards engage in combat with the agents, with Agent 22 reprimanding Scrooge about shouting a battlecry. Robots 1 and 2 are dispatched by Agent 22 while Scrooge knocks robot 4 into a piranha pool while Robot 3's arm is chewed off. The robot is beaned by Scrooge and tries to escape. Scrooge throws a stalactite at the robot but misses. Agent 22 reminds Scrooge that they can't leave any loose ends, but Scrooge assures her they won't see the robot again. Beakley soon gets separated from Scrooge and gets knocked out by Black Heron.
In the present, Scrooge is fighting off the still-functional Robot 3 and Webby kicks it into the piranha pool, with the piranha dead for years. Scrooge is impressed with Webby's resourcefulness and compliments that they should have done something like this more often, but Webby tells him that Beakley told her not to bother him because of his business and that she was busy with her training, ultimately preparing for another McDuck/Agent 22 adventure. Scrooge is impressed that she knows so much about him but sad that he knows so little about her, including the fact that Webby's favorite drink is juice despite gulping down an entire pot of tea. The two then find Black Heron's lab and watch the film Black Heron recorded years ago.
After strapping Beakley down, Black Heron records herself announcing she has engineered a bouncing juice she intends to use for global domination. Scrooge intercepts her session and the two fight over the formula.
While the duo are distracted, Black Heron knocks them out. Scrooge and Webby awake tied up and see Beakley imprisoned, the latter scolding Scrooge for bringing Webby into this. Black Heron then threatens to hurt Webby to force Beakley to give up the formula. After Heron concocts it, Scrooge notions Webby to loosen Heron's grip, causing her to drop the juice for Webby to drink it. Now endowed with bounciness, Webby frees herself and Scrooge. Heron drinks some of the juice and attempts to abscond with it as Webby bounces after her, while Scrooge frees Beakley, who was impressed with how much Webby could do. Bouncing up to the sky, Webby wrestles the juice away from Black Heron and pushes her away right when the formula wears off. Scrooge and Beakley rescue her but Heron escapes leaving her robot arm behind. The group then heads home with the juice in hand.
Scrooge tells Webby about what happened during their first fight with Black Heron. In order to help Scrooge, Beakley unbinds her wrists, drank the juice, and escaped to find the missing page nearby. After memorizing the formula, Beakley tore it up. Heron attempted to attack her, but the scuffle mixed several chemicals together and started a fire that costed Heron her arm. Scrooge and Beakley escaped, and Beakley decided to stick with Scrooge. Webby then thanks Scrooge for the experience, and Scrooge asks Webby to call him Uncle Scrooge. As she hugs him, the last remaining bottle of bouncing juice can be seen in her pocket.
- David Tennant as Scrooge McDuck
- Danny Pudi as Huey Duck
- Ben Schwartz as Dewey Duck
- Bobby Moynihan as Louie Duck
- Kate Micucci as Webby Vanderquack
- Tony Anselmo as Donald Duck
- Beck Bennett as Launchpad McQuack
- Toks Olagundoye as Bentina Beakley
- April Winchell as Black Heron
- Corey Burton as Ludwig Von Drake
- Keith Ferguson as Auctioneer, Randy
- The episode is inspired by the spy genre and British spy classics:
- Scrooge and Beakley's 60's attire heavily resemble the characters of John Steed and Emma Peel from the television show The Avengers (completely unrelated to the Marvel superhero team of the same name).
- Beakley's code name of Agent 22 is a reference to Agent 99 of Get Smart.
- While S.H.U.S.H. and F.O.W.L. have appeared in Darkwing Duck prior, they are meant to be clear references to CONTROL and KAOS from Get Smart as well as The Man from U.N.C.L.E.
- The bubble bodyguard with a derby hat could be a reference to Oddjob from Goldfinger. The bubble bodyguard is also possibly a reference to the character Rover from the 1967 British sci-fi series The Prisoner.
- This episode features Easter eggs from Disney's Adventures of the Gummi Bears, such as silhouettes of the Gummi Bears main cast in the scroll, the mentioning of Dunwyn Castle, and the formula for Gummiberry Juice. Also, Black Heron's mugshot number 09141985 references September 14, 1985, the date the show premiered.
- The last bottle of Gummiberry Juice that Webby takes home, will again play a minor role in the series finale "The Last Adventure!"
- In a bit of foreshadowing, Scrooge introduces Webby to Black Heron as "Webby VanderDuck" instead of "Webby Vanderquack", not knowing the connection that Webby has to Black Heron, or even to himself; all of which is also revealed in the series finale.
- This episode confirms the existence of the S.H.U.S.H. and F.O.W.L. organizations in the series. Before this, both were alluded to in previous episodes; F.O.W.L. was on the bulletin board in "Woo-oo!", and S.H.U.S.H. was advertised in "Beware the B.U.D.D.Y. System!".
- Scrooge mentioning a crook named "Jack the Tripper" is a reference to the minor villain from the original series, Professor Moody Doody, from the episode "Dr. Jekyll & Mr. McDuck" and the infamous London murderer Jack the Ripper.