Easy going event coordinator Katy Costa is called in last minute to sub for her perfectionist sister at a Christmas Eve wedding in Portland, Maine. Nice guy chef Cole St. Onge takes over from his temperamental boss for the same event.

The problem? Each thinks the other is their prickly counterpart and they expect fireworks when they meet. It's the sparks that fly between them that's unexpected. And unwelcome—Katy's skittish after a bad breakup. Left at the altar, Cole's sworn off women for good. Mix in an unexpected snowstorm, an accident-prone groom, Katy's self-pitying ex making trouble, a matchmaking grandma, and lots of mistletoe, and what's supposed to be a magical holiday affair fast becomes a Christmas nightmare.

Forced to team up to put out the many fires, the blaze between Cole and Katy burns brighter as the evening wears on. Can they ignore their growing attraction and keep their relationship strictly professional? Or will they give in to the mistletoe and say I do to a Christmas kiss that promises more to come in the new year?