The Autobots go on alert as the Decepticons return to Earth in the series opener, Meanwhile a group of humans find themselves with new caretakers after stumbling into the middle of the Autobot conflict with the Decepticons.

The Autobots go in search of Cliffjumper, whose life signal is weak and find Megatron wielding the dangerous dark Energon.

Bulkhead is unknowingly shadowed by Miko as he goes to rescue Agent Fowler, who was kidnapped by the Decepticons.

The Autobots try to stave off an attack from Megatron's Terrorcons to protect their human wards.

The Decepticons and the Terrorcons go into battle against the Autobots.

Starscream pursues other interests while Skyquake battles with Optimus Prime and Bumblebee.

Scraplets invade HQ while Optimus and Arcee patrol the Arctic, leaving Bumblee and Ratchet to repel the enemy.

Bulkhead awaits a visit from his buddy Wheeljack, but his arrival does not go as planned.

The Autobots are attacked while helping Agent Fowler transport an implosion device.

Miko and Bulkhead go up against Starscream and Breakdown as they go to Greece to retrieve an Energon Harvester.

Jack tries to be impressive, with Bumblebee's help, but Knockout's arrivals sends things out of control.

Arcee must protect Jack when a routine mission is complicated by Airachnid's arrival.

A Decepticon plague infects Optimus Prime, so Arcee and Bumblebee sneak onto the Nemesis to find the cure.

Megatron controls Bumblebee from inside his mind and influences his behavior at HQ.

The kids are stranded with Skyquake in an alternate dimension during a GroundBridge malfunction.

MECH agents capture a Decepticon, and the Autobots mount a rescue.

Airachnid makes a deal with Silas to get revenge against Arcee and Jack.

The Autobots try to claim a magnetic weapon before the Decepticons get to it.

Two patrolling Autobots end up trapped in a cave with their enemies, Starscream and Megatron.

Starscream makes an unexpected request after he is captured by Optimus.

Bulkhead acquires a top-secret formula, and the Decepticons come after him for it.

Ratchet becomes a threat to everyone after he injects himself with an experimental substance.

The Decepticons quickly try to build a space bridge before a prophesied darkness arrives.

Earth has an outbreak of natural disasters, caused by Dark Energon.

The Autobots acquire a surprising ally in their battle to save Earth.

The Autobots go to the Earth's core to fight for the planet; and Jack uncovers info about Optimus' background.

Megatron manipulates the impaired Optimus into joining the Decepticons.

Jack learns how to restore Optimus' memory.

Optimus begins to piece together his real identity using several clues (including Starscream referring to his as a "prime" -- whoops!), and eventually rebels against Megatron’s orders. Meanwhile, Optimus' Autobot pals hatch a risky plan to get their leader back.

Bumblebee questions his worthiness to his team after he is compromised.

Bumblebee discovers that MECH and Starscream are responsible for his troubles; Ratchet confronts demons from his Cybertronian past.

Wheeljack returns to Earth, hot on the the trail of Skyquake's brother Dreadwing.

Megatron sends Dreadwing, Airachnid and Breakdown to investigate the trail of a potential Energon source, but what Airachnid doesn't know is that Dreadwing and Breakdown have actually been ordered to kill her for her treachery. She eventually catches wind of this, however, killing Breakdown and running off into the woods. Upon arriving at an abandoned Energon mine, Airachnid encounters Starscream cowering from a large Insecticon. After using her abilities to control the creature, she contacts Megatron and tells him to come to the mine, planning to use the Insecticon to kill him so she can claim Decepticon leadership...

Following from the events of the previous episode, Agent Fowler is sat down to explain recent events to his superior, the cynical and disbelieving General Bryce. Threatened with a military tribunal and Team Prime's termination, Fowler tries to convince the General that the Autobots are still on the military's side, but the General believes that Optimus Prime went rogue and has perished, failing to fully understand that Nemesis Prime was not the real Optimus.

Bulkhead is trapped on the Decepticon Warship and amid dual tries on Megatron's life.

Megatron infuses The Nemesis w/ his own supply of Dark Energon which results in the ship taking on a life of its own with its own agenda. Meanwhile Optimus reluctantly decides to use the Spark Extractor in an attempt to bring the war to an end.

Megatron goes on a conquest to reveal the rest of the relics while Arcee and Bumblebee race him to New York City before Megatron gets there.

Optimus Prime travels to Antarctica to hunt down the second relic, but while there he is confronted by Dreadwing and Starscream, and finds himself caught between shifting alliances.

During a relic hunt, Ratchet and Wheeljack get a one-of-a-kind opportunity when Soundwave's flying minion, Laserbeak, is disabled.

Bulkhead, on mission for the fourth relic, came back in critical condition via ground bridge. What happened?!? One epic showdown as Bulkhead and Hardshell go head-to-head in the ongoing quest to gather the last of the Iaconian relics on Earth.

Miko and Wheeljack embark on a quest for revenge.

Arcee and a friend uncover a feat of Decepticon engineering intending to destroy the Autobots.

Starscream goes on a quest for Red Energon; a new Autobot joins Team prime.

After being granted a new start in his life, the ever stone-faced Silas begins to see the world in a new light and makes an out-of-character decision to go to Megatron in the hopes that he will be allowed to join the ranks of Decepticon.

Now that the location of the relics have been exposed by Orion Pax, the race is on to find the next one. New recruit Smokescreen and Jack are on the job with the Autobots looking to cut down Megatron before the beats them to it.

The Autobots find out about the Omega Keys and their secret. Meanwhile, Megatron attempts to control the power of the Primes.

As the race for the Omega Keys grows more desperate, Knock Out harnesses the power of sound, and Starscream the power of hyper-speed.

When the Decepticons take him captive, Smokescreen learns of the location of the final Omega Key - and attempts to retrieve all of the other stolen keys from Megatron.

In an effort to secure a peaceful truce that would be beneficial to all parties involved, Starscream offers Megatron a ceasefire but Dreadwing has other ideas and does whatever he can to keep the diplomatic agreement from taking place.

The Autobots and Megatron's Decepticons are drawn into Cybertron to face each other in a heroic battle over their mutual quests for the coveted Omega Lock, which, once unlocked with the four keys, would reawaken Primus'

Due to Megatron's crafty plan, Optimus must make a hard decision which could affect the whole Autobot team.

While Optimus struggles to survive after Megatron’s destruction of the Autobot base, the separated members of Team Prime try to reconnect.

The Autobots search for signs of each other, but start to lose hope while the Decepticons welcome a key player to their ranks. A win for Wheeljack may ultimately lead to an Autobot defeat.

The Ultimate Autobot Hunter is unleashed on our heroes.

Led by a new member, Team Prime launches a desperate assault on the Decepticon citadel.

The Decepticons launch a new scheme to clone an army of beasts.

As tension builds within the Wreckers, they find themselves confronted with the return of the Predacon.

Unlikely duos team up, including Acree and Wheeljack, and Agent Fowler and Jack's mom.

Knock Out and Starscream experiment with synthetic lead and threaten to take over the Deceptacon ship and unleash an old enemy.

Megatron doubts Predacon and its allegiance after Predacon reveals a secret of its own.

Soundwave is captured by the Autobots; Megatron revives an old plan.

While Optimus faces off with Predaking, Megatron mounts a campaign to form a new alliance.

Ratchet finds himself in a series of predicaments as he resumes his experiments on Synthetic Energon.

The Autobots face the Decepticons for a final showdown.