After the chaos of "Man vs. Bee", Trevor Bingley has taken a quieter job as a school caretaker. A lucrative Christmas penthouse gig lures him back — and when no one collects the Baby Jesus from the school nativity, Trevor finds himself with an unexpected companion over the holidays.
Trevor's Christmas preparations take an unexpected turn when he's left in charge of a lost baby just as a lucrative house-sitting offer falls in his lap.
After passing the house-sitter interview while keeping the rascally baby out of sight, Trevor faces his next challenge: changing nappies.
If being locked out of the penthouse and dealing with nightly intruders wasn't enough, an unfortunate mix-up leads Trevor to part with the wrong baby.
An unexpected bit of news from the penthouse owners sends Trevor into a mad scramble to save Christmas — and the baby — from disaster.