In a small town in Nebraska, Hermione Granger, who is being played by Elizabeth Bennet, and Harley Quinn have just completed their first case, rescuing Pamela Isley from the Joker. After the rescue Hermione invited Harley to join her new Detective Agency, H&H Detective Agency. Hermione arrives and excitedly announces that they have their first client! Her ex-boyfriend from high school, Ron Weasley, asked if they could look into a letter he received threatening to blackmail him. Harley is relieved, having become restless in their tiny office in a closet in the back of antique shop.

At the local print shop, Hermione and Harley interrogate the owner, a nervous Mr. Jenkins, who seems to be hiding something, but Harley's unorthodox methods threaten to derail the investigation.

As they leave the print shop, Elizabeth confronts Harley about her unorthodox methods by threatening Mr Jenkins with violence and sabatoging his business, leading to a heated argument about their differing approaches to detective work.

Hermione and Harley have a tense reconciliation at the local diner, where Harley reveals a surprising insight into the case, forcing Elizabeth to reevaluate her opinion of Harley's unorthodox methods.

As they investigate Ron's past, Hermione and Harley discover a shocking secret that could be the key to the blackmail, but Harley's enthusiasm for the revelation is tempered by a rare moment of vulnerability.

Harley asks Hermione what Ron was like in High School and why they broke up. Hermione explains that they were good friends, but Ron's true love was always Ron. Harley can empathise, given her experience with her ex-boyfriend. They bond over their shared experience with self-centered ex-boyfriends. Harley then asks if Ron had any enemies in school, any that might stoop to blackmail. One name comes to mind. Draco Malfoy.

Hermione and Harley devise a plan to investigate Draco Malfoy, with Harley insisting on using her own unorthodox methods, while Hermione pushes for a more subtle approach.

Hermione reluctantly agrees to Harley's plan, and they sneak into Draco's mansion disguised as maids, with Harley's antics causing chaos and Hermione struggling to keep a straight face.

As Draco approaches, Harley and Hermione quickly hide in his office closet. Harley whispers that Draco's office closet is bigger than their closet office. Harley can't see so Hermione whispers that she sees Draco looking stressed and reviewing a hand written ledger. They agree that they need to get a look at the ledger.

As Draco leaves the room, Harley and Hermione sneak out of the closet and make a beeline for the ledger. Hermione tries to read the ledger but it's encoded. Harley says she loves puzzles and very quickly figures out the cipher. Hermione is amazed and impressed with Harley's skill. It's a blackmail ledger. Draco has been using knowledge of his high school friends secrets to blackmail them. But it looks like he's still struggling to make enough to fund his lavish lifestyle.

Hermione believes they have enough information to go to the police and get Draco arrested for blackmail. Harley points out that if they go to the police, all of Hermione's friends secrets will be revealed. Harley proposes that instead they should blackmail the blackmailer. They should take the ledger and send an anonymous letter to Draco saying if he does not repay his victims, then they will go to the police and ruin his reputation. Draco gets a taste of his own medicine. Hermione is impressed with Harley's cleverness and unorthodox approach.

Harley and Hermione agree that they need to smuggle the ledger out of Draco's mansion but they're still in their maid costumes. They agree that they need to sneak from room to room. Despite her best efforts to stay professional, Hermione starts to enjoy the thrill of the adventure. They find the exit but it's blocked by Draco's two henchmen friends from school, Vincent Crabbe and Gregory Goyle. Hermione tells Harley they need a distraction and that she should bring the chaos. Harley is surprised and excited and quickly tells her her plan.

They've escaped! Hermione is still laughing and asks why Harley brought fireworks and silly string on what was supposed to a mission to search for evidence. Harley says you always need to be prepared for chaos. Hermione thanks Harley for all her help on this case. She couldn't have done it without her. Harley tells her she was happy to help, plus being able to watch her in a cute maid costumer was the best part. Hermione blushes heavily and asks if Harley really thinks she's cute.