A creature made of energy called Tornedron is unleashed by Primacron. Tornedron goes to Cybertron and completely drains the planet and all Autobots on it of energy within seconds. Primacron sees this and is pleased, believing Tornedron to already be more successful than his previous creation, Unicron. Meanwhile, there is a large battle going on between the Autobots and Decepticon's on the Earth's Moon. But a voice then calls out to the primitive Transformers -the Dinobots, Sky Lynx, Terrorcons, Predacons and any cassette Transformer with an animal alternate mode. The voice tells them to come to him, so the Transformers board Trypticon, who then takes off along with Sky Lynx and heads to the place where the voice is calling them from.

The remaining Transformers have no idea what's going on. But Tornedron then arrives and drains energy from the Moon and then Earth. Primacron has seen the primitives have gone and has Tornedron follow them. The primitives arrive at their destination, and most of them enter a cave where the voice reveals the dangers of Primacron and Tornedron. The voice reveals that he was once Primacron's assistant. He and Primacron created Unicron, who turned on them. He was destroyed, whilst Primacron survived. He hopes that the primitive's simpler instincts will be enough to defeat Tornedron.

Tornedron then arrives and drains Trypticon. Trypticon falls and seemingly crushes Grimlock, whilst the remaining Transformers try to fight Tornedron. However they are unable to stop him -their attacks simply make him bigger, and he ends up draining all Transformers of energy. Tornedron then returns to his master, but Grimlock blasts his way out of the ground. The voice tells him he must find Primacron's lair and destroy it. Grimlock sees Tornedron heading away, so he follows.

Primacron realizes he can no longer control Tornedron. Tornedron reveals he's going to destroy Primacron. Primacron desperately tries to find a way to stop Tornedron, just as Grimlock smashes his way into his lab. Primacron says he's tried everything, but Grimlock says he'll solve the problem, and moves a lever down. This happens to be the reverse switch, which causes the energy polarity of Tornedron to be reversed. Tornedron is forced to go back to wherever he's been, and any energy he'd taken is given back. Soon all planets and Transformers are restored, whilst Tornedron is destroyed. Grimlock says he's saved the universe, and starts stomping around with joy. He destroys Primacron's lab in doing this, and Primacron yells at him for ruining it. Grimlock tells him that's the smartest thing he's ever done!

Notes

-The Secret Files segment for this episode is about cassette Transformers.

-As you might have noticed from the above images, this episode's animation and art is really high quality, this is the best looking episode of the series by far. The episode was meant to be animated by Toei, but they sub-contracted it to Studio Look -click here for more details.

-When Kup first starts talking, you can very briefly see Windcharger running out of the shot:

Which is a bit surprising since he was seemingly killed off in the Transformers movie... I guess he got better?

-Overkill and Slugfest make their debut in this episode... and do nothing. They are seen flying out of Soundwave and transform, but then they aren't seen again. As Laserbeak and Buzzsaw are missing, some fans believe they were switched out at the last second for Overkill and Slugfest, as they had new toys (that weren't even on store shelves when this episode first aired in 1986 -they'd be out in 1987) -but that's just speculation.

-The voice that calls the primitives is referred to as the Oracle in the dialogue script, but this name is never spoken in the episode itself. Instead the Oracle refers to himself as "Primacron's assistant".

-When Primacron's assistant dies, there is a shot of his corpse and the Autobot Matrix of Leadership rising out of it. This scene has caused a great deal of confusion with fans to what it means, so much so that the wrier of the episode was asked about it... and he didn't have a clue! Some believe that the appearance of the Matrix was an error, but it's unknown what the real intention of the scene was.

Errors

-Rodimus is missing his spoiler during this shot.
-The Oracle calls Sludge "Sweep" when he names the Dinobots.
-Galvatron's chest insignia is colored red instead of purple when he contacts Trypticon.