Superman stories throughout every age includes those where he suddenly appears to, or actually does, work on the side of the bad guys. In Action Comics #63 (June 1943), we get the first such story, in which invisible rays from two stars colliding in the cosmos strikes Clark and not only wipes out his nipples (?) but gives him amnesia and wouldn’t you know it, criminals happen to be walking by at that moment and recruit him as one of their own.
Even with his amnesia, I love how Superman recognizes how to respond to a threat, it’s his most endearing quality: Always doing the right thing.
Of course destroying the threatening meteor restores his memory!