A
financial crisis in Springfield causes the sale of many houses and release of all low-level criminals from Springfield Penitentiary, including a man named Walt Warren. Walt purchases a house next door to the Simpson family and charms the neighborhood. However,
Bart is convinced that Walt is
Sideshow Bob in disguise because they have the
same voice. He tries several times to find proof, but fails.
Marge convinces him otherwise by taking him to the penitentiary, where they see Bob locked in a
padded cell, wearing a
straitjacket and writing "Bart Simpson Will Die!" on the walls. A seemingly reassured Bart decides to go to a
baseball game with Walt, who removes his small shoes to show long feet folded inside, revealing himself to be Sideshow Bob. Bob restrains Bart in the car and gags him with duct tape, planning to take him to
Five Corners, a location where five states meet, to kill him. Meanwhile, the real Walt Warren escapes prison while bearing Bob's hair and face and comes to the Simpsons' home. At first, everyone thinks Bob has escaped, but Walt's short feet reveal his true identity. Walt explains that he and Bob were cellmates and, prior to Walt's release, Bob drugged him and performed a transplant to
switch their faces. The transplant left Walt unable to talk properly, resulting in him being detained in the padded cell. He wrote his message on the wall as a warning, but it was misinterpreted as a threat. Walt and the Simpsons go after Bob. Meanwhile, a waitress at a roadside diner becomes infatuated with Bob until she peels off Walt's face. Amidst a distraction outside the diner, Homer, Marge, and
Lisa travel to Mexico in search of Bart while Walt gets away and continues to the Five Corners. At the Five Corners, Bob intends to kill Bart in such a way that the crime takes place in
all five states (Bob stands in the first, fires the gun in the second, the bullet travels through the third, hitting Bart in the fourth so that he falls dead in the fifth), thus making it impossible to prosecute. Bart stalls by repeatedly jumping into the same state as Bob until Walt arrives. Walt and Bob struggle over the gun, but just before Bob can fire on either Walt or Bart,
Chief Wiggum and the Springfield Police Department arrive to arrest Bob. Wiggum reveals that Bart had reported his suspicions to the police, who confirmed Bob's identity through
DNA profiling and tracked the
GPS in his car. Bob jumps into the other states in order to escape their jurisdiction, only to be promptly confronted by police from each state and taken into custody. Walt is then officially released while Bob's house is bought by
Ned Flanders' cousin Ted, and Homer is annoyed at the realization that he now lives next door to
two Flanders families. ==Production==