Out in South America a group of archaeologists are busy digging through a hill when they find something metal. More digging is done and to their surprise they find what appears to be a spaceship! They soon work out that the ship must have been there for millions of years and soon their find is on the news. However, the Decepticons learn of this and when Megatron sees it he says that he wants something that is on that ship.

At the Autobot HQ, Perceptor is trying to fix one of Ironhide's chips but that jerk Brawn is also there and is finding Perceptor's attitude of not thinking fighting is the most important thing ever hard to take. As Perceptor works Brawn continues to hurl abuse for no reason until Bumblebee comes in and tells him to lay off him. Optimus then enters and says that they need to roll out to South America as the Decepticons are headed there but Perceptor says he can't go as he has too much to do at the base. Prime lets him stay whilst Brawn acts unsurprised by Perceptor's wimpyness.

The Decepticons can't fly to their destination as they want to avoid satellite detection, and so they start to blast the surrounding jungle to pieces even though the local wildlife puts up a bit of a fight about it with Starscream being attacked by a snake (which Rumble and the Constructicons think is funny) and Ravage having to fight a leopard. The Autobots arrive and see that the Decepticons have cleared a path they can use but they move with caution.

The Decepticons reach the site and get the humans there to scatter. After that is done it is revealed that the ship the humans found is actually the ship the Decepticons had used to follow the Autobots millions of years a go. Megatron goes inside it and gets the thing he wanted - the "Heart of Cybertron", which he has Hook implant into his chest.

The Autobots arrive and attempt to stop the Decepticons but they are too late and Megatron shows that he has become much more powerful by blasting the Autobots with lots of laser blasts from his fingers. These shots chew through most of the Autobots and Optimus believes that Megatron must have the Heart of Cybertron, as it is the only way he could have become so strong so quickly. Smokescreen then causes a diversion...

...and the other Autobots open fire on the mountain which sends a lot of rocks tumbling down and crushing the Decepticons. Optimus knows that won't hold them for long and so the Autobots head back to base so Ratchet and Perceptor can start fixing them. Prime tells the medics to fix Wheeljack first as he needs him to create a force shield for when Megatron arrives.

Perceptor is fixing Powerglide when the lights start to dim. Optimus walks in and says not to worry as he has had most of the power in the base diverted into creating a force shield in the hope that it will be able to stop Megatron. However Perceptor has also thought up a plan -using his machine, he will shrink himself down to a microscopic size and enter Megatron, and then proceed to take out the Heart of Cybertron. Optimus thinks that this is a good idea as he hadn't thought up a plan yet at all and tells Bumblebee and Brawn to go with him. Soon the Autobot trio and shrunk down and put into Powerglide.

Out in the open Megatron proposes a toast to their upcoming certain victory over the Autobots and the Decepticons proceed to do a bit of energon drinking. A little bit too much actually as soon all of them are staggering about and falling over. Powerglide arrives and finds his task of shooting a little box with the three shrunken Autobots inside a lot easier than he though as the Decepticons don't put up a fight or even notice him. In fact, Megatron only wakes up when he feel something hit his chest.

The Autobot trio get out of the box and jump down one of Megatron's arm sockets as the Decepticon leader gets up and sees Powerglide flying away. He tells his troops to attack but they are all wasted so he decides to just go and destroy the Autobots himself. As he starts to fly towards the Autobot base, Perceptor, Brawn and Bumblebee begin their journey to try and find the Heart of Cybertron.

The come across all kinds of things inside Megatron's body, including electro-sanitizers that try to destroy them but Brawn destroys a few of these. They make it up Megatron's shoulder joint as they make their way to his chest section but before they get there they find Megatron's brain unit. It is very quiet in this section and Perceptor say that it is because Megatron is not currently using his brain as he is simply flying through the sky. Brawn wants to destroy it but the other two Autobots stop him, with Perceptor stating that it is too dangerous.

Perceptor's reasoning is that if they destroy the brain Megatron will fall and the Heart of Cybertron could detonate, which could do untold damage. However, suddenly a creature appears which Perceptor identifies as a "brain impulse" and loads of them start to appear, which means Megatron is using his brain - and has begun his attack on the Autobots. One of the impulses attacks Bumblebee but Brawn kills it.

Perceptor then works out that the impulses are being created from the brain giving orders to the Heart of Cybertron - so if they follow one they will be taken to the place they want to go. They go for a ride on one as Megatron mocks Prime for having a pathetic force shield set-up to try and stop him. Meanwhile the mini Autobots arrive at the Heart and Perceptor starts to rip apart the wires connected to it.

Megatron destroys the force shield and then attempts to finish off the Autobots for good but he suddenly can't fire any more! As he wonders why Optimus sees that Perceptor and the others have managed to complete their task so he shoots Megatron in the chest, which causes him to fall onto his back. The Autobots inside Megatron have got the Heart of Cybertron and quickly head back to a way out as the affects of Perceptor's machine are wearing off - they are returning to normal size!

They make it out in time as Megatron sees them and after throwing a hissy fit, heads away in disgust. Wheeljack wants to go after him but they have a much bigger problem -the Heart of Cybertron has been destabilized and is about to explode!

So Brawn just throws it as high up into the air as possible as Perceptor transforms to microscope mode to track it. Once it reaches 2000 miles, he then shoots it and the thing explodes with a large fireball. With the day saved and the Autobots still in one piece, Ratchet says that they have just saved Megatron's life but Brawn says that thanks to one Autobot all of their lives have been saved and shows his new found respect for Perceptor by saying that he's a hero.

This episode has really nice animation, some of the best in the series actually.

When Optimus heads out to South America he takes just Brawn, Bumblebee and Ratchet with him. But after the first commercial break, suddenly Cliffjumper, Bluestreak, Ironhide, Huffer, Smokescreen, Windcharger and Hoist have appeared out of nowhere to join the party. Optimus also calls out Grapple's name at one point, despite that character never appearing in the episode itself. And then once the Autobots arrive back at base, it's revealed that Gears, Wheeljack and Powerglide were also at the battle, despite never being seen there.

Maybe Brawn should have killed Megatron. Then his death probably wouldn't have happened. That'll teach him for being a jerk to Perceptor though.

The Decepticon ship is not named in the episode but was later given the name Nemesis in things like Beast Wars. The back end of it doesn't look the same as it did in the first episode mind you.