How Many Herring In A Wheelbarrow?

A security guard at RX Chemical Laboratory is paid a midnight visit by a peculiar man with an even more peculiar car, and you could say he's also got a peculiar greeting card. Wait, that's not a peculiar greeting card - that's the Joker!

The nefarious Joker and his jester-themed goons bust their way inside by, literally, knocking the wall down with a giant robotic fist. I wish I was shitting you. Once inside, he snaps a few photographs of some top secret documents and, just for giggles, decides to pinch a beaker of fish on his way out. Red herrings, to be precise!^[1]

The Joker then breaks his way into Gotham planetarium, which is enough for the Bat Signal to be raised to summon the dynamic duo to the scene, but it turns out that only a few worthless trinkets were taken from both locations. Robin ponders why a thief would go to such effort to only steal a bunch of tat, but is told to look through the telescope, which has a picture of the Joker at the end of the lens. Yeah, don't ask.

Joker has made himself busy over at the Solar Dynamics building, where his group tunnel underneath it precisely enough for a security guard to plummet down a perfectly circular hole, allowing the Joker to photo some blueprints. He's not far from finishing his master plan, he claims! This time he decides to take a wheelbarrow with him. Why? Dude's bananas, that's why.
 

Batman and Robin are summoned once more, but Batman's catching onto the game. Robin's still clueless, so he recites an old tale - there was once this guy who left a building every night with a wheelbarrow full of sawdust, and it was only two weeks later someone realised he was stealing wheelbarrows. True story. The beakers and wheelbarrows are cover-ups for something bigger - as is made evident when the two are told the Joker was spotted at the Gotham Industrial Laboratory! They arrive and pursue the Joker's car, though another white car is in their way.

They realise that no one's driving the car and it is merely a remote-controlled decoy, so they puncture its tires. The Joker is prepared for such a situation and blows up the goddamned road. Seriously! The decoy car is lost in the process and it looks like our heroes have no chance of tracking the Joker, but thankfully, the remote control transmission from the Joker allowed the Batmobile to get an eye on his car, so they can figure out where his hideout is. Don't you love impractical technology?

While the Joker gloats about his assumed victory in his funhouse hideout, Batman and Robin arrive at the scene, but Joker isn't taking this sitting down. He liked the irony of how they escaped his explosion-based trap earlier, and now he's going to dunk them into a hot and heavy situation. So he drops them through a trapdoor and onto a slide which they are pinned to by a magnetic force!

The Joker applauds them for realising this so quickly, but dares them to escape the impending threat of being scorched alive! I mean, seriously, they're magnetized to the slide - however will they escape?

By turning the power switch on their utility belts to "full" which creates an electricity shock to demagnetize the slide. It's a pretty crummy solution, personally.

The two return to the Batcave where the Batcomputer will tell them the connection between the two laboratories and all the heat-related threats the Joker has been dishing out.

It turns out that four scientists at those places had been involved in the development of a giant solar mirror, and the last thing the Joker needs in his plan is the electronic detonator at Gotham Light And Power - that solar mirror could totally level a city in a short space of time, and knowing that the Joker has the right plans and tools to make (and/or steal) the mirror, they need to stop him!

The Joker has already arrived at the Light And Power facility, having shipped himself in an exploding gas-filled crate. And to make sure no one outside bothers him, he remotely detonates his transport van. The Joker sure loves blowing the hell out of things.

The Joker gets what he needs out of their via helicopter, and by the time the dynamic duo arrive at the scene, the building is a smouldering wreck. They talk things over with a scientist back at planetarium who tells them that a solar mirror requires a whole facility to power it, and there's only one place with the right tools and enough sunlight to charge that tool - the abandoned powerhouse just outside of Gotham!
 

The Joker makes some heat-related puns while admiring today's evil scheme, and knowing to avoid walking into a trap this time, Batman and Robin choose to enter by ejecting themselves into the air and onto the roof (using the Bat Ejector, no less), preparing to swing in and take care of Joker's goons.

And indeed, they do just that, using a variety of swinging hooks, barrels and stock footage to achieve their goal. In the scuffle, however, the Joker flees and activates the solar mirror, locking it in the On position!

In a pure video game moment (a good couple of decades before that kind of nonsense became mainstream!), the two duck and weave their way through crashing pistons to reach the nerve centre of the solar mirror. The sizzling electrodes will need disabled in a very scientific manner - but this is a kid's show, we can't make the solution too scientific! It's a good thing for reversing the polarity as that's the solution they opt for, which requires hitting the electrodes with their batarangs at precisely the same time. In another video game trope, those are load-bearing electrodes - the whole place is going to blow!

The Joker is still fleeing from the scene as Batman and Robin escape, but he's too far ahead for them to catch. It's a good thing that when the place went kablow, the observation dome was propelled into the air and happened to land on the Joker, pinning him to the ground. "Why me?! Why does it always happen to me?!" he laments.

Quick, twenty seconds left for the wrap-up! Chief O'Hara recounts to Bruce Wayne and Dick Grayson about how if it weren't for the dynamic duo, the Joker would surely have blown up the city or something awful. The two ask for the chief to continue, winking and nudging the camera because whoo he's talking about us and commenting "it sounds like a hot one!" Because fire jokes are funny after the whole city was under risk of being boiled alive.

¹No, I don't know why a chemist had red herring in his lab, never mind why they were inside a beaker. I guess a model ship in a bottle just isn't exciting enough for everyone these days.

When the Joker arrives in the Light And Power building he renders some scientists unconscious with the gas, and they're not seen escaping before the place is burnt to the ground. Unless that was a different building. It could very well have been a comprehensible plot, but when working with limited animation like this it's kinda hard to tell!

Either I'm a perverted son of a bitch and trying to account for the lack of females in the show, or Robin has a bad habit of being drawn with rather lady-like feet and with his legs in particular focus. Wouldn't be anything new in either case, mind you, but thought I'd share.