During the war on Cybertron, the Mini-Cons, mini-transformers who can be used as upgrades by their bigger brethren, crash lands on Earth. In present day, a group of children finds their ship by accident which brings the war to Earth.
Escaping from the confrontation between Bots and Cons, Alex, Rad and Carlos find the cargo hold of the Exodus underground and are adopted by three minicons. Retreating to the moon, the 'Cons make the wreck of the Exodus there their base.
Alexis, Rad and Carlos introduce themselves to Optimus Prime, Hot Rod and First Aid, and get a condensed history of the conflict. Meanwhile, on the moon, Megatron plots to capture the minicons that are now appearing all over earth.
The children join the Autobot team and head out on their first mission to find a newly waking minicon. The Decepticons arrive to combat them. Optimus Prime finds his old minicon partner.
The newest minicon activates in the middle of a forest: both sides fight for it, and the conflict sets the trees alight. The Autobots attempt to battle the blaze, while Starscream finally acquires his own minicon.
Rad and Carlos smuggle their minicons out of the base to visit the town's carnival. Billy and Fred see them transform and try to capture one, but are thwarted by Hot Shot.
The Decepticons capture all the children to use as hostages in exchange for the Autobots's minicons. Fred and Billy are officially introduced to the Autobots.
The latest minicon re-activates in the subway system of a large city, and there's the usual scramble to see which side can get to it first. And a new transformer makes himself known - but which side is he on?
From an ancient submerged city a beautiful girl issues a warning about the devastating power - and danger - of three special, combining minicons. The Autobots already have two of them: now Megatron aims to capture the third.
The children learn more about the history of the minicons and the war. The latest minicon alert leads the team to a volcanic island: the volcano erupts in the middle of the usual 'Bot vs 'Con battle.
The Decepticons gain access to the Autobot base, and attempt to take the other two minicons that, with the one Megatron captured on the island, combine to make the supremely powerful Star Sabre. Can Hot Shot save the day?
Hot Shot proves himself very skilled with the Star Sabre, but the arrival of a new Decepticon proves him overconfident. The Decepticons acquire the first of another three combining minicons which transform into the ultimate form of defence.
A new minicon activates inside a highway tunnel, and the race is on to see who reach it first. Hot Shot is becoming more proficient with the Star Sabre. A new transformer arrives, claiming to be an Autobot, but Rad has his doubts.
Grabbing onto Megatron at the end of a battle, Hot Shot and Sideways are transported to the moon. The battle resumes, but Hot Shot is betrayed, and Starscream gains the Star Sabre.