Sophie is preparing for Christmas without her late husband, Frank, trying to maintain some normalcy for her son, Matthew. Despite the emotional challenges, she’s determined to give him a happy holiday. However, tensions rise when her mother-in-law, Rachel, unexpectedly arrives, criticizing Sophie’s parenting and offering unsolicited help. Things escalate when Sophie discovers a hidden camera inside their Elf on the Shelf, which records her every move.

Sophie confronts Rachel, suspecting her involvement in an attempt to discredit her as a mother and take Matthew. But the true betrayal comes when Sophie discovers that her own mother, Liz, planted the camera. Liz admits she wanted proof that Matthew would be happier living with her, believing Sophie wasn’t managing after Frank’s death. Sophie is furious and demands Liz leave. As her mother packs, Matthew asks why, and Sophie reassures him he will never be taken away. Despite the turmoil, Sophie is determined to protect her son and their life together.