In the aftermath of Cybertron's catastrophic orbit of Earth, Starscream seizes control of the Decepticons and puts into motion a plan to destroy the planet.
- Japanese title: "Operation: Obliterate Earth"
- Russian Tv dub title (6th channel): "Отсчет гибели" ("Countdown to Extinction")
The previous threat of Cybertron's orbits over Earth have passed. Optimus Prime and the Autobots work to help repair cities and do other generous/benevolent type things. After all, Megatron is MIA, believed killed in the explosion that moved Cybertron from Earth's orbit. But they are not the only ones to notice Megatron's absence.
Starscream, believing Megatron destroyed, forces Doctor Arkeville to take him to his secret laboratory. Once there he discovers another of the Doctor's inventions, the Exponential Generator, a power source that, if it overcharges, will detonate with enough energy to destroy the Earth.
Seeking to gain power for himself, Starscream links the generator to a timer and then takes Doctor Arkeville with him to Cybertron which is still nearby. He plans to collect the energy unleashed by Earth's destruction to revitalize Cybertron. He coerces Shockwave into serving him, and helping in the restoration of Cybertron.
Meanwhile on Earth, Megatron has returned to the Decepticons having survived the explosion of his starship. When he learns that Starscream and Doctor Arkeville are apparently working together he sets off in pursuit with the other Decepticons.
The Autobots detect the Decepticon activity and set off after them. After a short battle the Autobots are trapped in quicksand. Ironhide freezes the quicksand with his liquid nitrogen allowing them to escape. Laserbeak, who was standing guard over them, is captured and Jazz forces him to play his findings. The Autobots learn that the Decepticons are heading for the Doctor's secret laboratory and they set off to follow them.
The Doctor, unwilling to let Starscream benefit from the Earth's destruction, attempts to sabotage the energy collectors but the Decepticon security system stuns him with a blast of electricity. Starscream has the badly-injured Doctor 'repaired' by the medicroids, leaving him more machine now than man. Of course, he was twisted and evil to start with, so.
The Autobots arrive at the laboratory and battle each other again. Unaware of the danger it represents, Megatron covets the exponential generator and fights Optimus Prime for its possession. During the fight Megatron receives a communication from Shockwave on Cybertron.
Shockwave, unwilling to serve Starscream, warns Megatron about the timer and Starscream's plan. Megatron rips the timer from the wall just in time. On Cybertron, Starscream is baffled that the Earth has not exploded and sets off back to check the timer.
The exponential generator has become volatile and begins to go critical, ready to explode. Prime rips it away from Megatron, but the Decepticon leader says he needs the Autobot leader's help. Transforming, Megatron tells Prime to load the generator into his gun barrel, and then fires it into space. It explodes and the blast sends Starscream crashing to Earth where Megatron is waiting for him.
With the threat ended, the Autobots let the Decepticons go. Bumblebee wonders what will happen to Starscream, and the other Autobots are amused at the thought of what Megatron plans to do.
"Hey, I didn't volunteer for this geeky assignment. I want Skywarp's job."
"Butt out Frenzy. Geek work's made for a geek! Like you!"
- —Frenzy and Skywarp bickering before resorting to violence.
"Hey Optimus, how'd you like to hear number one on the Decepticon hot cassette charts?"
"As I believe the earthlings say...Lay it on me, man."
- —Jazz and Optimus Prime
Rumble: "Megatron, it's...it's the Autobots!"
Megatron: Impossible! They were doomed!"
Skywarp: "Don't worry. We'll make them regret undooming themselves."
- —The Decepticons prepare to kick some exhaust port.
"Now load me!"
- —Megatron to Optimus, unknowingly creating plenty of opportunities for bad fan-fiction.
"Welcome home, noble voyager."
- —Megatron being more than sarcastic when he greets Starscream.
“Hey Prime, what do you think Megatron's gonna do to Starscream?”
“Nothing gentle, I would say.”
- —Bumblebee and Optimus Prime, after Megatron is last seen carrying Starscream off screen.
Original Air Date: December 1, 1984
- During the reconstruction, there's a brief shot with two Brawns, one handing the other a concrete block. In the next shot, one of them has turned into Gears, in time for Huffer to hassle him.
- In the beginning, when Megatron returns and there is a shot of Decepticons standing in front of him, Skywarp's chest is colored black.
- When Megatron returns, Thundercracker's chest has four lines instead of the Seeker's usual two.
- Just after that, when Laserbeak flies into Soundwave's cassette holder, it briefly becomes blue like the rest of Soundwave's body, but during the close-up, its coloring changes to Laserbeak's red-and-white.
- The damage caused to Megatron's chest by the exponential generator disappears after he leaves the lab.
- How is it that everyone seems to know where Doctor Arkeville's secret laboratory is?
- The explosion from the exponential generator is supposed to be powerful enough to destroy the Earth, and yet the actual explosion is so small, all it does is knock Starscream out of the air. (See also "War of the Dinobots" for another example of an "Earth-destroying" explosion).
- While this episode is supposed to take place immediately after "The Ultimate Doom", the Japanese continuity places that three-parter at the end of the series, leaving everyone clueless as to how Starscream and Arkeville know each other and how Arkeville is turned back into a human from a cyborg.
- Apparently, Optimus Prime doesn't mind insubordination from his troops, as shown when Wheeljack claimed, "Take cover? I don't want to take cover," and proceeds to fire on the Decepticons.
- Takes place almost immediately after "The Ultimate Doom, Part 3".
- Frenzy first appears in this episode — and he's red.
- As proof of his leadership, Starscream shows a badge with the Decepticon symbol. Every other leader just had Laserbeak perch on his shoulder or arm.
- The existence of an "exponential energy generator" has profound implications for everything we think we know about the laws of thermodynamics.