It’s Christmas time in Caerphilly and the town is preparing for their live nativity.
During rehearsals, Meg discovers a real baby in the manger, with a note attached that says the mother is leaving the baby girl there so her father can take care of her, and the wording of the note implicates Meg's brother, Rob, as the father.
Rob protests that he can't possibly be the father, but the town suspicion creates a rift between him and his new girlfriend. Rob asks Meg to investigate on his behalf—to clear his name and to find the real parents of the baby. But every day that passes without answers is another day that spoils everyone's enjoyment of the holiday and drives the wedge between Rob and his girlfriend deeper.
As Meg gets further into her investigation, she discovers the found baby is connected to something much bigger, a crime that will need to be stopped by Meg and her motley crew to save the holidays for everyone.