The episode picks up where the previous left off, with the two new armored guys attacking Decade and Kuuga.

After a short fight I guess Stupid Hat Man calls in another dimensional riff, the new guys jump “into another hell,” as one of them says. Stupid Hat Man vows that this is just the begining, and walks away. I have no idea what the point of any of this was.

With tempers cooled, Tsukasa, Natsumi, and Yuusuke finally get to talk like civilized people. We find out that Tsukasa is convinced that by stopping the ritual in the previous episode he’s saved the world from the “Ultimate Darkness” that is sleeping under a nearby mountain. For his part Yuusuke explains that when he received the belt that transformed him into Rider Kuuga he was told that someday a devil called “Decade” would appear and destroy everything. Who told him this? None other than Stupid Hat Man.

After this revelation the conversation is interrupted by Grandpa’s TV. Black smoke is coming from the nearby mountain, signifying that the Ultimate Darkness awoke anyway. Ane, who was investigating the mountain, is fatally poisoned and taken to the hospital. The smoke rolls into town and everybody who chokes on the gas turns into a Grongi. The rest of the episode is very much like a zombie movie in tone. Yuusuke sits at Ane’s bedside while Tsukasa transforms into Decade and heads off to fight the growing horde of Grongi, headed by Ultimate Darkness himself.

Initially Decade gets his plastic chaps handed to him, but Yuusuke (as Kuuga) arrives to help with the fight, having been convinced by the dying Ane to fight for the good of humanity. Actually there this whole weird thing about fighting for smiles that carries through the rest of the episode, but I’m going to gloss over that.

After fighting the horde for a little bit Decade swipes the card for “Final Form Ride: Kuuga.” Kuuga transforms into a giant robot beetle.

The Kuuga-beetle grabs Ultimate Darkness out of the air. Decade swipes a card for “Final Attack Ride: Kuuga,” gives Ultimate Darkness a flying kick and that’s the end of U.D.

Tsukasa and Yuusuke arrive back at the hospital and find out that Ane died while they were gone.

Tsukasa and Natsumi go back to the photo studio. Tsukasa explains that the world has been saved. Then Grandpa accidentally drops another background the studio, this one showing the dragon/mansion combo from the first episode.

I guess we’re off to the next world.