Optimus finds an interesting-looking plant under a large rock. Dinobot is summoned, and voices his low opinion of plants, when being a target out in the open is taken into account. Optimus explains that the Maximals are explorers, and their mission is to learn about new planets and species. Dinobot wants to prepare for conflicts with the Predacons, and Optimus claims the environment is part of conflict. Dinobot relents, and decides to fetch the plant by blast the rock. Optimus stops him, pushing the rock aside instead. Optimus points out his non-violent approach. Dinobot gets angry, insults the plant and starts to leave. The plant shoots a pod that gets stuck to the back of Dinobot's neck. Dinobot freaks out, and Optimus pulls the pod off, which hatches into a new plant.
Scorpinok arrives, and attacks Dinobot and Optimus. During the fight, a rock is knocked onto Dinobot, pinning him to the wall. Optimus moves to aid him, and Scorponok shoots at Optimus a bee, which attaches to Optimus' chest. Optimus returns fire, knocking Scorponok onto a log, which falls over a waterfall. Dinobot frees himself of the rock, and the bee injects Optimus.
Back at base, Dinobot is being criticised for failing to back Optimus up. Optimus is in the cryo-regeneration chamber, and Rhinox explains that Optimus can't transform with the bee on his chest. Cheetor suggests removing the bee, and Rhinox reveals that would kill Optimus, before setting off a mine in the bee that would kill anybody nearby. Dinobot suggests that Scorponok has infected Optimus to turn him into a coward, and notes that Scorponok probably has an antivirus. Optimus busts out of the cryo-chamber, brandishing his arm cannon and threatening the Maximals. Optimus is very angry, and warns them not to take the bee off his chest. Rhinox restrains Optimus. Dinobot notes that Scorponok has not turned Optimus into a coward, but instead into a bezerker. Cheetor tells Optimus to fight the virus, and Optimus tells them to take away his guns and lock him up.
At the Predacon base, Scorponok tells Megatron that Optimus has been infected. Megatron, believing that Optimus is now a coward from the virus, hopes that the Maximals will attack the Predacons to retrieve the virus, and due to Optimus' ailment, will lose.
Optimus has been locked in a cage, with lasers. Optimus convinces Cheetor that he can restrain the virus, and Cheetor frees him. Upstairs, Rattrap and Rhinox listen as Dinobot proposes his idea of equipping loose-cannon Optimus to the teeth with weapoons, before sending him off to fight the Predacons and retrieve the antivirus. Rhinox points out that Optimus would probably end up dead. Cheetor and Optimus arrive, and Optimus agrees that storming the base is a good way to get ahold of the antivirus. Rattrap questions his own safety in this plan. Optimus gets angry and shoots a fire alarm. More alarms go off, and Optimus starts shooting up the base. Rhinox tackles Optimus, with Cheetor and Rattrap piled on top. Optimus throws them all off. Optimus calls the Maximals cowards for not wanting to attack the Predacons, and leaves. Cheetor prepares for battle, while Dinobot explains why fighting is a bad idea. Dinobot puts himself in Optimus' pacifist shoes, and decides to negotiate.
Terrorsaur points out a transmission coming from the Maximals, and opens the line. Cheetor explains to Megatron that Optimus has gone crazy and is going to destroy the Predacons, unless they surrender the antivirus. Megatron says no, and closes the line, before smacking Scorponok for messing up the virus. Cheetor admits to the Maximals that the negotiations failed, and now the Predacons will be waiting for Optimus to show up. Dinobot takes off Optimus' shoes, and decides to put his own back on.
Optimus blows a hole in the Predacon base and flies in. Blackarachnia warns Megatron that Optimus is in the base, and Megatron tells Tarantulas to destroy Optimus. Tarantulas gets behind Optimus, and shoots a spear. Optimus catches it, and charges Tarantulas. Tarantulas shoots Optimus a lot, to no avail. Optimus grabs Tarantulas and pins him to the wall with the spear. Blackarachnia tells Megatron that Tarantulas has failed, and the other Maximals are approaching the base. Blackarachnia is sent with Terrorsaur to fight the Maximals, while Waspinator is charged with stopping Optimus. Waspinator searches for Optimus, but gets scared and backs up against a wall. Optimus tears through the wall, grabs Waspinator, throws him aside and shoots him. Outside the Predacon base, Dinobot, Cheetor, Rattrap and Rhinox fight Blackarachnia and Terrorsaur. When Cheetor gets the chance, her runs inside.
Optimus makes his way to Scorponok's lab, but collapses. Megatron has the antidote and begins taunting Optimus. Megatron wants Optimus to join the Predacons, in return for the cure. Optimus rips the bee off, initiating the self destruct. Megatron throws the antitode in the air and starts to leave. Optimus throws the bee, which gets stuck to the back of Megatron's neck. Megatron runs to Scorponok for help. Cheetor arrives, catches the antivirus and stabs Optimus. Optimus is cured, and both leave the base quickly. The Maximals retreat. Megatron demands Scorponok remove the bee bomb. Scorponok pulls it off Megatron a moment before it detonates. A huge explosion rocks the Predacon base.
The following day, Optimus wakes up, to find Dinobot at his side. Dinobot is glad to have Optimus back. Optimus notices a flower next to his bed, and Dinobot leaves. Optimus takes a nap.