Wilykit and Wilykat decide to one-up the bolkens from episode 11 and release an even bigger badass that was imprisoned in an ancient tomb.
We open in a burning building on a goat-man with a big scythe. He hops up onto the roof and proclaims, “no creature, no structure, no Third Earthling will escape the wrath of Mongor. Mongor is fear. Fear and destruction!”
He waves his scythe around, which spreads more flames. We zoom out, and see that Mumm-Ra has been watching the whole thing in his cauldron. Mumm-Ra explains, “Mongor terrorizes Third Earth, and wherever he finds fear he grows in power and strength. Soon he will be fit to destroy the Thundercats!” (And since it’s Mumm-Ra, you can assume there’s some laughter interspersed in there).
Speaking of the Thundercats, we cut to Cat’s Lair. Inside, we see that they are experiencing some kind of mysterious earthquakes, and their scanners are being blocked by some kind of force field. We cut outside, where Wilykit and Wilykat are riding their spaceboards, but having trouble with them, and decide to head back to Cat’s Lair.
Out in the Thundertank, Lion-O, Panthro, and Snarf are experiencing equipment problems, too, so they also head for the lair. With all the Thundercats in the control room, Panthro declares everything back to normal. Tygra points out that each time the disturbance happens it gets worse. Wilykit and Kat try to sneak out the back while everyone is talking, but Snarf catches them and demands to know where they’re going. The try to dismiss Snarf, but all the other Thundercats crowd around them and give them the third degree.
Eventually, they admit that they caused the mysterious problem. Panthro finds this hilarious, because he finds it impossible to believe that two kids had anything to do with something that could affect Cat’s Lair. Cheetara asks Wilykit and Kat to explain what they mean. Wilykit starts talking, leading us into a flashback: “It all started when we were at the ruined temple.”
In the flashback, Wilykit and Wilykat are flying their spaceboards. “Hey, Wilykat, let’s take a look at that ruin.” “Sure, looks like some kind of temple.” Wow, who would have expected something like that at the ruined temple?
Inside the temple, Wilykat sees a giant stone hexagon with pictograms carved into it that are reminiscent of Mongor. Wilykit suspects that it might be a tomb. His first impulse? Open it.
As they move the stone, we see that the skies are darkening outside, and a thunderstorm is starting. Then (still in Wilykit’s flashback, remember) we cut to Mumm-Ra’s pyramid. We hear Mongor’s voice calling out to Mumm-Ra. Mumm-Ra is pretty stoked to hear from Mongor, since he’s been trying to free the dude for three centuries, but hasn’t been able to find his prison. Mumm-Ra watches what Wilykit and Kat are up to in his cauldron, and we cut back to them. They move the stone far enough to see that there’s a hole underneath, but then the stone moves the rest of the way on its own and a giant column of fire bursts out of the hole.
Mongor materializes in the flame, claiming to be the “eternal image of fear”. Mongor starts out the same size as Wilykit and Kat, but despite their protestations to the contrary, they are clearly afraid of him. Some yellow lightning goes off between Mongor’s horns as they feel the fear, and Mongor grows slightly.
We do a wavy transition back to the Cat’s Lair control room to signify that the flashback is over (so I assume that cutaway to Mumm-Ra really was a part of it). The adult Thundercats start really chewing out Wilykit and Wilykat for their irresponsibility, and we cut to Mumm-Ra who is happy that Mongor is already sowing dissension in the Thundercats’ ranks. We cut back to the lair, where Snarf is trying to stop the criticism firing squad.
Snarf adopts the “they’re only kids, how do you expect them to learn?” line of argument (and I am still confused about why they’re kids, because they came to Third Earth in the same kind of suspension modules that Lion-O did and he aged to maturity). Snarf thinks that being overly angry with Wilykat and Kit will just make them too frightened to come to the other Thundercats when they need help. Meanwhile, while the other Thundercats are discussing them, Wilykit and Kat slip away. Lion-O finally notices that they’re gone, and the Thundercats decide they all need to split up and search for them.
Back at Mumm-Ra’s pyramid, he’s been watching the action and thinks that Mongor now has the perfect opportunity to take out the Thundercats one at a time.
We cut to Tygra in a forest. He gets the sensation that something is following him. He whips some leaves into the air and turns invisible, but this only seems to amuse Mongor, who we hear laughing. “You cannot hide from Mongor with your Thundercat tricks!” Mongor sends in some black smoke which makes Tygra visible again. Tygra figures he’s outclassed, so he whips out a big bulky communicator (didn’t Panthro integrate the communicators into the Thundercats’ weapons in episode 15?).
Before Tygra can get through to anybody, Mongor zaps the communicator with some lightning, knocking it from Tygra’s hand and destroying it. Mongor charges Tygra, but Tygra leaps out of the way.
Tygra ignites the end of his bolo whip and tries to strike Mongor, but Mongor just grabs the flaming end of the whip in his hand, completely unaffected by the fire, and throws it back at Tygra. The bolo ends on the whip hit a tree, and they extend like giant lashing tentacles to form a giant web among the trees in the forest. Mongor uses his scythe to shoot some blue fire at Tygra. Tygra’s whip then wraps around him, incapacitating him.
We cut to Wilykit and Kat on their spaceboards. Wilykit thinks that the carvings on the rock that were imprisoning Mongor might be useful, since they were made by whoever trapped Mongor in the ruined temple.
We cut to Cheetara, who is speeding past a mud pit. A crab-man like the one Panthro fought back in episode 15 rises up out of the mud to accost her. She runs in circles around him, disorienting him, and dumping him into the mud.
Mongor appears at the top of a cliff. As he jumps down to attack her, he asks, “looking for your striped friend, Thundercat?” Mongor tries to shoot her with a column of blue fire from his fingertip, but she keeps running ahead of his aim. He switches tactics and shoots a bunch of threads from his fingertips. They weave into a net around her, trapping her (This also means that Cheetara has officially taken top honors from Snarf in the “Thundercat most frequently caught in a net” competition. There’s this episode, episode 14, and episode 12).
Back at the ruined temple, Wilykat and Kit discover a pictogram that seems to indicate that Mongor’s power can be reflected back at him, and that a key defense against him is to not look at him directly.
We cut to Panthro, driving in the Thundertank. The ground cracks open in front of him, opening into a large chasm. Panthro uses the front paws of the Tank to grab the other edge to try to pull himself across, but some kind of yellow lightning is shot from the chasm which causes the tank to lose its grip and start falling into the chasm. Panthro activates the rocket thrusters on the tank and starts to fly out, but is zapped by lightning again, so his landing is very rough. Mongor rises up out of the chasm, looking pretty big now, since he’s been gaining power from the fear of the Thundercats he’s defeated. Panthro decides to see how Mongor handles some “stellar rated laser power”, and zaps him with the laser cannon in the Thundertank’s nose.
Mongor just laughs it off, and then reflects the beam back at the tank with his scythe. He then uses some eye-beams to lift the tank into the air, flip it over, and drop it.
Panthro emerges from the tank and tries to take on Mongor with his nunchucks. He whips one end at him, and the little paw on the end opens up to reveal a hole that shoots out some gas.
Mongor just sucks the gas up through his nose, and makes like the big bad wolf and starts blowing Panthro away. Panthro figures he needs an anchor, so he shoots the spikes from his suspenders out into the ground, with lines attached, to stabilize himself.
Mongor stops blowing. Panthro retracts his spikes and tries to run up for another attack, but Mongor causes Panthro’s spike-lines to freak out and start flailing around. They tie Panthro up and anchor him to the ground.
We cut to Mumm-Ra, still watching all the action in his cauldron. “Two children and the youth Lion-O, all that stands between men and my perpetual reign of evil!”
We cut to Lion-O and Snarf. Lion-O tries to use sight-beyond-sight to find Wilykit and Kat, but can’t. He’s also troubled that none of the other Thundercats have checked in. Mongor shows himself, and Lion-O immediately decides to call for help. “Thunder, thunder, thunder, Thundercats, HO!” With a series of quick cuts, we see that Panthro, Tygra, and Cheetara are still all trapped, unable to answer the Thundercats signal.
Lion-O and Mongor fight, Mongor using a few of the same tricks that he’s used on the other Thundercats. Lion-O seems to be standing up pretty well, leading Mongor to realize that he may have underestimated Lion-O. Mongor switches to straight-up scythe attacks, and knocks the Sword of Omens out of Lion-O’s hand. Just then, Wilykit and Kat fly in on their spaceboards, and Wilykat uses his lariat to grab the sword.
Wilykat throws the sword back to Lion-O, and Wilykit warns Lion-O not to look at Mongor. Mongor uses his flame breath to knock Wilykit off of her board, but Lion-O pulls her to safety with a line from the Claw Shield, and Wilykat pulls her up onto his spaceboard. Kit and Kat both chew up some capsules from their belts to unleash a giant swarm of bubbles. Mongors tries to shoot his eye-beams, but they are refelcted back at him by the bubbles.
Lion-O uses the reflective properties of the Claw Shield to line up an over-the-shoulder shot with the Sword of Omens. Mongor gets zapped, and appears to be in a lot of pain.
We do some quick cuts to the trapped Thundercats, and the forces that have been holding them in place seem to be weakening. Another zap with the Sword of Omens, and Mongor is rapidly shrinking. We cut to the other Thundercats, who are able to free themselves!
Back at the fight, Lion-O no longer needs to avert his eyes from Mongor, because he doesn’t fear him anymore. “I no longer fear his power. And without fear, he is nothing.” Mongor is banished back to his ruined temple.
We cut to Mumm-Ra’s pyramid, where Mumm-Ra says that the power of the Thundercats was greater than he thought, greater than anything he has overcome before. He goes back to his sarcophagus to rest.
In the coda, the Thundercats are back at the ruined temple, where Panthro is welding Mongor’s prison shut.
Tygra tries to cast more blame at Wilykit and Wilykat for their role in the whole thing, and they respond that it was an accident. Cheetara claims that Tygra was just teasing, but I’m not so sure. Snarf and Lion-O are of the opinion that Wilykit and Kat redeemed themselves, and it was brave of them to come back to the ruined temple. They explain that they were really brave, just more afraid of the Thundercats’ anger than they were of Mongor.