Type-A Ava owns Rent-an-Elf, which sets up Christmas for busy families. This year, she's hired by newly-single Liam and falls for him and his adorable son Nathan. But just as Ava thinks she's found her match, Liam's ex-wife returns, wanting to patch things up. Though disappointed, she's still determined to give them the best Christmas ever, and maybe even hope for a Christmas miracle or two.