S8E16: Brother from Another Series

In "Simpsonlar - S8E16," which is the episode titled "Brother from Another Series," Sideshow Bob is released from prison and claims to have reformed. He's given a job by his brother, Cecil, as the chief hydrological and hydrodynamical engineer of Springfield's new hydroelectric dam. Naturally, Bart and Lisa aren't buying Bob's change of heart and decide to investigate. Their suspicions seem justified when they discover a plan to blow up the dam. However, it turns out that Cecil is the mastermind behind this scheme, aiming to frame his brother while pocketing the project's budget. Bob, surprisingly on the side of good for once, tries to stop Cecil from carrying out his plan. In the end, it's a chaotic showdown at the dam where Bart and Lisa manage to help Bob thwart Cecil's plan. Despite saving the day, Bob is arrested again due to his criminal past. The episode wraps up with Bob accepting his return to prison with a touch of resignation, as Bart remains ever suspicious of him.