The film centers on the Herdman kids, who are the absolute worst. They lie, they steal, they bully… and they’ve hijacked the town Christmas pageant. As the rowdy and raucous siblings force themselves into all of the lead roles, they drive the pageant’s director, Grace (Judy Greer), and other members of her family, including husband Bob (Holmes), up the wall. But through their misfit mischief, these unlikely messengers might turn out to be the ones to deliver the town’s sensational and moving portrayal of the true meaning of Christmas.

女演員Laura Franco（梅麗莎·巴雷拉 Melissa Barrera 飾）被男朋友甩掉后心碎消沉、懷疑自我，此時，她在自家衣柜里碰上了住在那里的一個可怕又古怪、迷人的怪物（湯米·杜威 Tommy Dewey 飾）。