When Max is fascinated by an intriguing autistic child he wonders if his own lost child is attempting to reach out to him. Meanwhile, Michael plays Santa to Maria and Liz's elves at a charity event. Isabel and Jesse share their first holiday together as husband and wife.
Max, Isabel and Michael have been hiding a secret for their entire lives - that they come from a different planet. When Max is exposed while saving Liz's life, a girl who attends their high school, it eventually leads to a few others learning their secret. The three aliens and their new friends try to go about their normal lives while trying to discover more about where they come from and how to get home - all while keeping their identities secret from the rest of the world.