Double-O Dodo

S2, E31: Vulture loudly fires Dodo again, and Headmaster Crane takes pity and hires him as an assistant. But when Dodo is caught trying to steal the plans for a new engine that Coot is working on for an upcoming competition, Crane realizes that the firing was a charade: Dodo was sent as a spy! Instead of turning him in, however, Crane decides to turn Dodo into a double-spy, sending him back to Vulture with fake plans. The new mission: to bring back the design plans that Vulture's team is working on. But Vulture quickly catches on too, and flips Dodo again, returning him to Crane as a triple spy. The silly Spy vs. Spy espionage continues to escalate, finally coming to a head at the big technology competition where Crane and Vulture square off - and conclude that by working together, they can better solve the design problems both sides were experiencing.