Melanie Welch is a hard-working ad executive who finds herself teamed up with uptight coworker Donovan Goodwin to come up with the ultimate Christmas commercial for a new cell phone. To make things more complicated, Melanie is Donovan's Secret Santa in the annual office gift exchange. To keep her identity secret, she sends Donovan emails from Santa to determine the perfect gift for him. However, her plan comes to a halt when Donovan mistakenly assumes that another co-worker is his Secret Santa, prompting Melanie to work to show Donovan that she's his perfect Santa.