Enrique and Rebecca are separated but try to maintain traditions with their kids, Izzy and Sam, like buying a Christmas tree. Rebecca has to leave early because her boss summoned her.

Enrique and the kids take the tree to his mom's restaurant and begin decorating. Rebecca is way overdue with her next book, and they've already paid the advance.

Their counselor is annoyed that both Rebecca and Enrique are so busy with work that they haven't really talked. Rebecca is still angry that he gave her advance money to help his mom's restaurant, and now she's struggling with the book.

The kids visit Santa, and to prove his authenticity, he gives them a magic pen that will grant wishes that are true of heart. That night, Sam helps Izzy draft a letter, and she wants a puppy since they were happier when they had a dog.

Their grandma sees the Santa note, and the next day, a puppy with a red bow arrives. Izzy thinks Santa brought it. Enrique is an easy sell, but it's harder to convince Rebecca to keep the dog. She does this because she doesn't want to be seen as the mean mom.

When Enrique's sister, Maria, comes home, she urges him to work things out with Rebecca and reminds him that they grew up differently and Rebecca isn't used to overinvolved families.

The family watches "The Nutcracker" together, and then Enrique helps put the kids to bed. He and Rebecca have an intimate moment before they squabble again about schedules.

Maria catches Camilla playing Santa Claus as they decide not to grant the PlayStation wish.

Enrique's car breaks down, so he sends his new co-worker, Candice, to pick up the kids. This angers Rebecca because she doesn't know her, and she suspects they're dating, which just proves they need better time management.

The kids heard their parents fight and have more questions, while Rebecca admits to her boss that she misses when she'd write her books and Enrique would write his song lyrics. They'd inspire each other then.

Mr. Hines and Vanessa brought in Liam, a top illustrator, to assist with Rebecca's book. She decides to base it on the kids and Santa's magic pen.

The kids think their mom is lonely, so they ask Santa for a bouquet of flowers. This creates more trouble because she thinks they are from Enrique, but he suspects they are from an admirer.

Then, the kids decide they want an elf to help their mom finish her book, and when they hear about Liam, they think he's the elf. Liam joins the family at the holiday party at the restaurant.

Enrique hates him on sight, especially when he wins Izzy a polar bear, and Sam thinks their dad is cooler.

After that, the kids ask Santa to reunite their parents, which nearly breaks Camilla and Maria's hearts. The kids are convinced Liam is going to ruin everything, so they run off to find Santa and ask him to fix everything.

They find Santa out of costume, and Santa remembers them, telling them that the magic of the wishes comes from within, not the pen.

Rebecca and Enrique are furious when they find the kids, but Enrique is also worried about how confused the kids are and maintains they need to fix things.

After they reconcile, he gathers the family to help finish Rebecca's book. It's amusing how everyone has rules for what Santa's pen can do, but it shows the strength of their family.

Camilla and Maria are busted as Santa's helpers. The next day, Rebecca presents her book, and it's a hit.

Enrique's present to Rebecca is a new song. The kids are happy to find both parents home Christmas morning.