All Bobs Must Die:

Up above the rooftops of Metropolis, a portal opened and unceremoniously spit out a teen in a Superman costume, before shutting again. Clark tumbled in the air a bit before righting himself. He wasn't certain what was going on. The last thing he'd remembered, aside from a blurry mess, was that he'd been somewhere above Los Angeles, rescuing a plane. He turned around, trying to get his bearings, and suddenly stopped.

He might not enjoy the Superman comics, but years of having them foisted upon him meant he could recognize many things in them by sight alone. The famous globe of the Daily Planet was one of them.

"What." Clark said flatly. He looked around, some more, enhanced vision picking out the Lexcorp Towers and Centennial Park.

"This can't be happening. I can't be in Metropolis. How am I in Metropolis?"