Gomez and Morticia are horrified to discover that Grandpa and Grandma Addams have a rare disease that is slowly turning them "normal". The only chance they have of curing them is to organise a family reunion, hoping that someone knows a home remedy. Unfortunately, due to a printing error, the family arrives at the reunion of an ordinary family named Adams (with one D). While Gomez and Morticia, oblivious to the mistake, search for a cure amongst a family divided by the wish to inherit; Pugsley and Wednesday are busy making new friends...explode; Uncle Fester and Thing search for a vicious Chihuahua that lives on human hair; and Lurch falls in love. Meanwhile, a couple going to the reunion are given the wrong address and end up at the Addams mansion where Granny and Cousin Itt are staying. No-one's life will ever be the same...