CREDITS: Written by Robert Goodman; directed by Curt Geda.
REVIEW: When I saw Roxy Rocket in the opening scene, I was overjoyed. She's really the only Batman villain who wouldn't take advantage of Batman's disappearance in Gotham to commit more crimes there, but having gotten bored, moves to Metropolis to face the threat of Superman. And so I was sad to see how quickly it was over.
But from there to Gotham City where, indeed, crime is on the rise in the wake of Batman's absence. Nightwing and Batgirl have foolishly left on a red herring (maybe Ra's did it), leaving Robin all alone to cope. So Superman decides to stick around, play dress-up and make the Bat seem truly unstoppable. Bane never saw it coming. The Riddler and Mad Hatter are also in this, both rather fun as simple villains (the episode isn't about their usual schemes), though the latter is a pretty poor, if natural, suspect once mind control is diagnosed.
The mystery is really the weakest part of the episode, because once you see the nanites, and knowing this is a Superman story, it's pretty clear we're dealing with Brainiac. HARDAC might have had a shot, but it would have been a remote possibility at this point. Superman's a little slow to put the clues together, that's all. And once he's caught in the act, all that's left is some action beats. Aside from the look on Brainiac's face when he discovers Batman is Kal-El, there's not very much to it. I would much rather we'd have spent more time with Superman trying to keep up appearances, or even a little more about the "Gotham Experience" which seems like the worst idea for a museum (were those mannequins thieves making off with loot?).
IN THE COMICS: Superman subbing for Batman or vice-versa was a fairly common Silver Age trope, and has been used since. Superman's ability to change his voice so perfectly is unique to the episode, though he'd been known to pull such tricks in the Silver Age, perhaps as a corollary of super-ventriloquism.
REWATCHABILITY: Medium - A fun story, but the villain behind the plot is no surprise at all.