Grace has four more days left of high school. Posner's Comet is about to come by. 

Two hundred years ago, Victoria Merriwick and Charlotte Posner were charting constellations when they saw a shooting star. When Victoria's wish came true, Charlotte got to name it when they discovered it was a comet.

Grace gets nostalgic about high school. 

Your comet wish only has a chance to come true if you wish on it while watching it from the Middleton Observatory build on the very spot it was discovered.

Adam reads the rave review about the food truck. They need to stock up on fixins, prompting an eye roll from Stephanie.

Stephanie wavers between wishing on the comet for food truck success or a 50 karat diamond necklace. Reviews don't ensure success, so they need to hold out hope for the truck.

Cassie is wearing a macaroni necklace Grace made when she was young. She's revealing all of the memories as she considers the kids leaving for college. Sam thinks there's something else, but she doesn't want to open up about it.

Martha visits the Bistro to complain about coming up empty with the key and to request a Monte Cristo. She discovers it's a food truck only option when she finds her husband eating lunch with Davis Donovan.

Abigail decides to borrow a book deemed the ultimate romantic tearjerker. The Stars in Their Hearts.

Grace gets a call. She's valedictoiran!

She's not as excited as she could be since she has to write a commencement speech about the future.

Cassie gives Grace the painting they found to take to the observatory.

Doug is their guest. A renwoned cardiologist.

Martha is aghast at Tom's friendship with Dottie and says she will not become BFFs with Dottie just because he's chummy with Davis.

Luke and Grace really like each other, and she wishes they would have met sooner. After her long distance relationship crashing and burning, she's not going to do another. He'll think of her everytime he sees a disco ball.

Martha talks with Donovan about Abigail. Did the curse break them up? Being well versed in all things Middleton and all things town lore appeals to Donovan. He wants to know how to break the curse.

When George brings in the birdhouse he and Grace made when she was six, she wants to make a new one.

Sam and Doug pluck the guitar strings in the living room.

Martha visits Bell, Book & Candle for a gift for Dottie. Cassie says to focus on who she wants to be instead of the recipient of the gift. Lemongrass and jasmine candle it is.

Stephanie is very worried about the success of the food truck afraid to even lift the window. She needent have worried.

Sam gets a call right after Grace admits she can't shake a bad feeling. There is a unique case at the hospital with a mirrored body.

Nick and Grace bicker while he films George and Grace. When they talk about how much they'll miss that, Nick suspiciously pulls away from the group.

Abigail is going to Europe. She needs a few weeks to clear her head, but Donovan keeps calling.

He sent her a typewritten note. There's a way to break the curse. Meet me at the fountain at 9 pm.

Martha thinks they should toss a coin in the well. Martha wonders if Abigail sarcastically tossed the coin. Cassie says you have to believe otherwise the curse will always win. 

Abigail is still going to Europe.

Donovan goes to Cassie's to ask about the curse. He breaks a mirror and laughs about seven years of bad luck. Only if you believe, Cassie reminds him.

Dottie tries to be mean when Martha enjoys their company, but she's only joking.

George uses Breezy's spreading his wings as an analogy for Grace spreading hers. Give yourself a chance, Cassie says.

Doug offers Sam a job. Chief of Surgery at Westbridge, a hospital in Los Angeles.

Grace takes Abigail dark chocolate peanut butter cups and assures her she'll like the end of the romance.

Stephanie and Adam are going nonstop, and he wonders if they should invoke Lisa Gold's name or thank her. Cassie drops by to find out they won't even make it to the comet watch because they're so busy. So she kills their grill.

Martha sees Dottie holding on to the past and trying to make herself significant. Martha is significant without needing to do that.

The observatory is packed. Everyone who is anyone is there. They all jockey to get good positions to watch the comet.

Abigail is getting a woman up to speed with her business when Dottie arrives. Dottie offers her gratitude to Abigail. The tension stretches between them to the point of breaking.

Doug and Cassie talk about fleeting things and the desire to keep them forever within reach. 

The comet comes into the sky and wishes are made across the lawn.

Sam spots the key around Martha's neck. Something hits him. The key is an arrow pointing to the next clue. It was demolished years ago! Just another dead end?

Breezy flies back to the bird house as soon as they put it up. "I guess he knew he could aways come home," Cassie says.

Martha sends Abigail a text about loose ends. She'll do it on the way to the airport. Donovan is in her office. Martha says someday she'll thank her.

Donovan opens an umbrella, walks under a ladder, and cracks a mirror. He doesn't believe in superstitions but when she came into his life it was good luck.

You invite 7000 years of bad luck onto yourself when you know something is worth believing in. She pops open the umbrella. They'll do it together.

Luke just got a full academic scholarship at Kenser. Everyone is very happy.

Nick knows it was Grace's wish because magic.

Cassie is pleased Nick likes Middleton so much he's making memories he can take with him. 

it wasn't Grace's wish about Luke. She wished Abigail and Donovan found their way back together. The real secret to wishing coming true is to wish unselfishly.

Cassie wished that Sam would do what made him happy, so he did. He turned down the job because what makes him happy is staying with her.