A series of mini-quakes at Autobot HQ leads to the Autobots finding a cave full of dinosaur bones. Spike takes Hound to a museum, where he takes holographic data of three different dinosaurs. Seeing how powerful dinosaurs were, the Autobots decide to build three robot dinosaur Transformers. They create Transformers who have triceratops, brontosaurus and tyrannosaurus alternate modes.

The Dinobots -Grimlock, Slag and Sludge -are all activated, and whilst they initially show how powerful they are, it quickly becomes apparent they can't be controlled properly. They begin to attack the Autobots and smash up Autobot HQ, including damaging Teletraan I. Wheeljack is eventually able to take them down, but Optimus orders for them to be deactivated due to them being too dangerous. The Dinobots are sealed back in the cave. Meanwhile, the Decepticons have attacked and taken over a power facility, and start making energon cubes.

The Autobots arrive and get into a fight with them, but Megatron uses a powered-up shot from his fusion cannon to blow up the ground they're on and make them fall into the river below. Bumblebee and Spike head back to base and report on what's happened. Realizing they have no other option, Wheeljack reactivates the Dinobots, but equips them with an invention he'd been working which should upgrade their brains and make them easier to control... he hopes. The devices are fitted and the Dinobots head out.

They arrive at the facility and easily overwhelm the Decepticons, causing Megatron to order a retreat. Whilst Bumblebee and Wheeljack and worried that they disobeyed Prime's orders, Prime says that even the wisest men and machines can be in error, so he has no reprimand for either of them. He also decides that as the Dinobots have proven their value, they will remain among them. The Autobots cheer as the Dinobots transform and roar.

Notes

-SCRIPT DIFFERENCES: Click here for details.

-It's the Dinobots! There's just 3 of them at the moment, but a couple more will be introduced a few episodes from now. This episode was first broadcast in 1984, but the toys for them weren't available in 1985, and they'd become some of the most popular characters in the series, especially Grimlock.

-Wheeljack's lights that come on when he talks are orange in this episode, as they were in this one. They were blue before this, and will be back to blue in future episodes.

-Megatron does something a bit out of the ordinary in this episode: he transforms without shrinking! Usually he always shrinks down, but not this time. It looks bit awkward when he attaches to the bottom of Starscream's jet mode though.

Errors

-What was causing all the rumbling is never brought up again after the Autobots discover the dinosaur bones.
-Ratchet says "Autobots meet Dinobots", but his voice is Wheeljack's.
-When Optimus says "Interesting, but what else can they do?", Cliffjumper's mouth moves.
-As the Decepticons approach the facility, there is an unknown Decepticon colored like Brawn among them.
-When Skywarp lands, another Decepticons lands next to him. You only see his leg, but it's colored orange, which doesn't match any known Decepticon.
-As the Autobots approach the plant, the Autobot symbol on Prime's trailer is missing.
-As the Autobots transform, Bluestreak transforms from robot to car instead of the other way round.
-When Rumble taunts Bluestreak, his eyes are colored gray instead of red.
-As the Autobots fall, Hound's missile launcher is missing.
-During this shot, Optimus is colored blue instead of red (although this does correct itself a few seconds later)
-Optimus is colored blue instead of red again during this shot.
-During this shot, Bumblebee's missing his chest Autobot symbol.
-The wrong music appears to have been used during the final scene, using a piece of music that's usually used for danger scenes.