Setting: Modern day. A small town in Pennsylvania and the ice cap of Greenland.
In a flashback to four years ago, the Patterson family—Air Force engineer Harry Patterson, mother Carol, Kami the high school valedictorian, and autistic little brother Ben—enjoy a family outing at the Hampton Hill Tree Lighting Festival. Although Carol prepares Ben for the over-stimulating environment, Ben has a small breakdown and escapes inwardly with his imaginary friend, his toy doll named Charley. As the scene dissolves into the following year’s festival, Harry, Ben and Kami (now a pre-med student at Yale) struggle with celebrating after Carol’s passing. Kami decides this is the last time she’ll put herself through the torture and decides to stop coming home for Christmas. (“The Perfect Christmas”) Over the next 2 years, Harry and Ben, with the assistance of a caretaker, finally establish a sense of normalcy. Weeks before Christmas, Harry is given a deployment on a top-secret mission. Giving the caretaker a break for the holidays, Harry asks Kami to come home to take care of Ben. Kami reluctantly agrees (“Let’s Fly”). Before leaving, Harry reassures Ben with a special compass (“Your True North”). Harry arrives on the ice cap of Greenland with orders to restore power to the military base (“Rest Up Ye Merry Gentlemen”). Not knowing the location or length of Harry’s deployment, Ben has a meltdown (“Tell Me”). On the ice cap, Harry unknowingly stumbles upon the North Pole. He is quickly sent away by disguised elves Snicker (a mechanic) and Junior Agent Skittle (NPCI—North Pole Central Intelligence) who argue on whether to keep his visit a secret (“In the Dark”). Drastically regressing, Ben becomes nonverbal, and Kami worries of her ability to meet Ben’s growing needs (“Say Something”). Deciding that his father must be home for Christmas, Ben writes a letter to Santa asking for his dad to be at the site of their family’s annual holiday hike—High Falls Bluff—on Christmas Eve (“Jolly Old Saint Nicholas”). Concerned about her job, Agent Skittle tracks Harry and discovers he has collapsed in the snow on the way back to base. Rescuing him, she brings him back to the North Pole and gives in to fully revealing their location (“The Best Kept Secret That Everybody Knows”). Confident that his request will be granted, Ben sets out for High Falls on Christmas Eve. Kami discovers Ben is missing and panics (“Make It Happen”).
Kami searches for clues to Ben’s whereabouts (“If I Were Ben”) and discovers scraps of Ben’s letter to Santa. While checking Santa letters, Snicker and Skittle discover Ben’s letter (“Kids These Days”). Snicker relays the news of Ben’s letter to Harry and offers to sneak him home in the sleigh, but the absence of reindeer (being groomed for the night’s flight) render it grounded. Harry finds the magic compass has mysteriously returned to his coat pocket, which Snicker claims has enough magic to power the sleigh. Stealing the sleigh, Snicker and Harry head for the Southern Yonder (“The Day We Hijacked Santa’s Sleigh”). Ben enjoys his independence hiking up the mountain to High Falls (“Sensational”), but after dropping his toy Charley down a large ravine, he retreats into a cave, unable to continue. Kami finds Ben and reluctantly agrees to continue with him up the mountain. Harry and Snicker arrive at the foot of High Falls. Harry takes the compass to find Ben, leaving Snicker stranded with the sleigh. Harry reaches High Falls and finds Ben and Kami. Ben is satisfied with his successful plan, and Kami finds a renewed love for family. Agent Skittle arrives to rescue Snicker and they all officially start the holiday season (“The Perfect Christmas Reprise”).