Grace is part of her high school planning committee along with her friend, Katie. Nick confesses to Grace that he wants to ask Katie to the formal but needs her help in doing so. Grace says she will help in exchange for Nick joining the planning committee. Nick obliges if that means he gets to work with Katie. Later on, Noah shows up to ask Grace to the formal and she says yes.
Abigail, Martha and Stephanie are trying to figure out who the mystery man is currently staying at Grey House but Cassie remains mum. Abigail jokes that she lives at Grey House and still doesn’t know this mystery guest, but the ladies do know he is single and arrived by private jet.
Determined to find out more about this mystery guest, Abigail decides to deliver tea. She finds a handsome man in a guest room strewn with paperwork. He introduces himself as Phil and explains he is in the middle of creating a new dating app for singles. He thanks Abigail for the tea and she smiles and walks out.
Sam is playing the piano with Cassie downstairs when Phil comes down. Sam wants to know more about his dating app and Phil explains it matches people based on open-ended questions with hand-written answers to see if potential couples are right for one another. Cassie has fun looking through the beta-testing applicants and discovers two mystery users in Middleton who the app says would be perfect for each other. Cassie is determined to find out who the two anonymous users are and wants to bring them together in real life.
Nick and Grace stop by to check out the flowers at Abigail’s shop for the formal. Once Abigail finds out the formal is in the gym, she insists it is time to find a better location, despite the fact that the dance is in just a few days. Abigail ends up going to Martha for permission to hold the dance in the outdoor park to go with the theme, “Under the Stars.” Martha says she will see if she can pull strings to waiver the fee and allow for the permit.
Sam and Cassie team up to find out who the mystery beta users were on Phil’s app. They re-examine the answers each of the users gave, hoping to search for more clues.
Martha is working on getting a permit for Grace’s dance. She gets annoyed when she sees a drone over the park. When the drone starts heading in her direction, Phil arrives and pushes her out of the way before it hits her head. Instantly, she is intrigued when she finds out Phil is Cassie’s mystery guest at Grey House.
Cassie and Sam’s search leads them to the high school, when they find out the female beta tester was an athlete there years ago. Using the little clues they have from Phil’s questionnaire, they track the woman--named Marian Anderson--down to the gym where she trains. Marian admits she was the one who filled out the questionnaire but thought it was all private. They assure that her identity is private but Sam is more interested in some of the answers she gave regarding her health and thinks she might need some medical attention, especially when it comes to her thyroid. She agrees to pay Sam a visit at the hospital.
Noah and Grace are on a date at the bowling alley and he quickly gets annoyed when she ignores him to fulfill her formal committee assignments. Grace is ecstatic to learn Martha got her the park permit. Grace tells Noah she has to cut their date short to take care of more details about the formal. Noah feels that Grace is not prioritizing their relationship and Grace quickly defends herself. She also promises Noah that no matter what, she will be at his game tomorrow night.
Abigail runs into Phil at Grey House and needles him for more information about his dating app. Abigail still wants to know how Phil believes he is matching people up with their perfect mate.. Grace interrupts their exchange and when Phil leaves the room, Grace points out to Abigail that Phil is interested in her. Abigail doesn’t believe Grace’s observation, but Grace says it was all in the way Phil stared at her during their conversation.
Back at the hospital, Sam tells Marian that his hunch was right: she has a hyper-thyroid condition and he suggests she make some changes to her diet and lifestyle. She wonders if one of the changes is finding that perfect catch that Phil’s dating app lined her up with. Sam laughs and says he wished he could find her that perfect match.
Grace is with her formal committee at the park, laying out the final details for the dance. Noah shows up in his uniform and it hits Grace that she missed his game completely. He tells her that they won. Their conversation is interrupted by Katie, who has a list of more responsibilities to take care of before the dance. A frustrated Noah tells Grace that if she is going to be too busy to enjoy the dance, maybe they shouldn’t go together at all.
Abigail finds Cassie in the kitchen and tells her of Grace’s observation about Phil. Cassie points out that Grace is usually spot-on when it comes to seeing when two people are into each other. The two are interrupted by a furious Phil, who accuses Abigail of stealing his dating app idea to create her own. Abigail says she has no idea what he is talking about, but he says Abigail is the only woman he trusted with the details of the app and he has discovered another tech company is building their own using his ideas. Abigail swears she didn’t say a word to anybody, while Phil tells her she will be hearing from his lawyers in the morning.
Grace goes to her mother’s shop to fill her in on Noah’s decision to not take her to the dance. Sam stops by with good news for Cassie: he tracked down Marian’s perfect match. Sam tells Cassie that he knew the mystery man had to be a sports columnist and he was determined to visit every newspaper in the area until he found the guy. Lucky for Sam, he found the sports columnist after his second stop and his name is Richard Stroud. Cassie agrees to go with Sam to meet Richard.
Martha finds Abigail at the bistro and wants to know where she can find Phil. When Abigail wants to know why, Martha explains that ever since that drone incident, she had the city ban them from the city parks. Abigail finds it suspicious that the owner of the drone disappeared after the incident and now she wants to identify him using the copy of his original permit.
Sam and Cassie get Richard’s address and head to his house. They find Richard’s brother Stephen, who is currently housesitting because Richard is on his honeymoon. Sam begins to question if he tracked down the right guy, after all.
Abigail confronts Phil in his room and tells him she thinks she knows who stole his dating app idea. She points out that Phil’s white board with all of his notes can be seen from the window of Grey House. Abigail suspects that the man with the drone used it to copy down Phil’s ideas. She tells Phil that the man’s identity is on the drone permit, and after she tosses it to him, she storms off.
On the night of the dance, Grace visits Noah at his house. She is wearing her formal dress and tells Noah she would rather be with him instead of at the formal alone, and all she wanted was a dance with Noah under the stars. She plays a song and asks Noah for a dance in the front yard and he takes her hand.
At the bookstore, Stephen engages in conversation with Marian. The two immediately hit it off over talk of Shakespeare. Cassie witness the exchange between the two and smiles.
The next morning Phil tracks down Abigail and apologizes for accusing her of stealing his ideas. Phil tells Abigail that she was right; the stolen idea was a plot driven by his former business partner. When Abigail gives Phil an icy look, he acknowledges that Abigail has every reason to be mad. Phil tells Abigail that he was able to keep his business patent for the app but he is not pursuing it, telling her that before creating an app about dating, he should learn a thing or two about relationships. He asks Abigail if she would be willing to teach him some lessons. Phil tells Abigail that he will be staying at Grey House for a while and maybe he will see her around.
The next morning, Grace is having a blast showing Sam and Cassie all of her photos from her dance with Noah in his front yard. Grace cuts her time short saying she has to leave for the baseball field to see Noah’s game. Nick stops her before leaving to tell her that because she bailed on the formal, he had to take over a lot Grace’s responsibilities at the dance. Just then, Katie walks in and thanks Nick for all of his hard work at the formal and suggests the two hang out outside the committee. Nick smiles and tells Grace that maybe he can help her with the prom committee, too.
Cassie tells Sam that she witnessed a sweet interaction with Stephen and Marian at the bookstore and in the end, the right people ended up together, after all.