Using the knowledge that the eccentric Addams family is looking for a lost family member, con artists come up with a plan to get one of them to pretend to be the long-lost Uncle Fester in an attempt to scam the family. But Morticia and Gomez Addams prove to be difficult adversaries to beat.
The members of the eccentric Addams family must band together when their beloved Uncle Fester marries their new nanny, who turns out to be marrying and killing rich men for their money.