Once the Stupids are reunited at home, Joan tells Petunia and Buster about Stanley's last job for the postal service where he discovered all the letters being marked "return to sender", but was fired before he could find out who "Mr. Sender" was. He tells his family about the conspiracy theory he has invented that combines all the ideas their overactive imaginations have created, including the "Evil Mr. Sender" plotting to steal all the mail and garbage from America and employing the police to kidnap anybody who discovers his scheme. When they find local museum curator Charles Sender in the phone book they set off in pursuit, ultimately tracking him to a television studio where Stanley appears on a talk show and is spotted by Niedermeyer who has him kidnapped and brought to the army base.