Pat has just discovered a picture of his Mammy Madeleine in the attic. He proudly shows it to Stan and Stéphanie. He would really like to hang it in the living room but Stan adamantly refuses which leads to a battle between the two friends and the picture finishes up in pitiful state. Annoyed, Pat goes to see professor Chi Chi to feed his hamster and discovers a strange invisibility paint. With this he can avenge himself against Stan by being the ghost of Mammy Madeleine.
