A wish-granting comet is headed to Middleton. The residents are all excited to go to the observatory to watch it as it only occurs once every 100 years. Nick and Grace get nostalgic as they deal with the last few days of high school. Adam and Stephanie are over the moon with glowing reviews of their food truck while Abigail is heartbroken over Donovan and decides to take a trip to Europe to get way from everything.
Martha stops by the Bistro – still on the search for the Middleton treasure – and stumbles upon Tom having brunch with Dottie’s husband Davis. She is outraged. Tom urges her to bury the hatchet with Dottie and requests they all gather to have lunch together. Donovan meets with Martha on town business but the conversation quickly turns to ways he can win back Abigail. Grace tells Luke she won’t do long distance and that they should just enjoy the time they have left together. Adam and Stephanie open the truck for the day and are amazed to see a long line of customers waiting. The two are concerned they won’t make it to the observatory to see the shooting comet, but when the grill goes out they take that as a sign to take the night off.
At lunch with Dottie, Martha is amazed at how great it is going. Later on when the two ladies are alone they start to clash again. Though Martha offers a peace treaty it looks like this is one rivalry that won’t be settled. Sam is offered his dream job across the country after performing a tricky surgery. Cassie is open to a change and says she will support him no matter. Later on, Sam turns down the job knowing his home is in Middleton with Cassie.
The town gathers at the observatory to view the comet and to make a wish. While there, Sam realizes the key that Martha found in the town’s charter is the key to the next clue. It leads them to the meeting house which unfortunately was demolished years ago, so the mystery continues. As Abigail is getting ready to leave for Europe, Martha asks her to stop by the town hall and sign some paperwork. When she arrives, she sees it is a set up for her to talk to Donovan. Donovan shows her that he doesn’t believe in superstitions as he opens an umbrella, walks under a ladder and breaks a mirror. Donovan asks for another chance and Abigail agrees to try it again, bad luck and all.