Transformers season 3, episode 10
Plot: Whilst fleeing from Galvatron who wants him destroyed, Octane makes friends with Autobot Sandstorm, and is no longer an Autobot enemy.
The Decepticons hunt him down and attack him on Cybertron. He accidentally takes refuge in a Decepticon crypt where he finds Starscream's ghost. The ghost (Starscream) takes control of Cyclonus and together with Octane concocts a plan where they both can get revenge on Galvatron.
Galvatron survives the following Autobot attack and returns to blast the Starscream-posessed Cyclonus. Cyclonus comes to, with no memory of these events. Starscream gets away safely, and takes residence in Scourge.
Now this is a weird, but nonetheless excellent episode. Not only does the wonderfully devious anti-hero Starscream make a welcome return, but we also get to see a Decepticon, Octane, who actually has good intentions when seeking contact with the good guys. The only other Decepticon I can remember doing anything like that is Blitzwing, another Triple changer who was exiled at some stage. (Perhaps the writers just mixed them up?)
One weak point in this episode is the fact that Galvatron hires the annoying little fat alien fishman to destroy Octane, something that of course just won't do. That alien dude is just too stupid and clumsy. Reminds me of an evil Jar Jar Binks, and that of course su**s a**...