Hate Plague

In the fictional universe of the Transformers, the Hate Plague, also referred to as a madness plague by Rodimus Prime, occurred sometime during or after the year 2006 and resulted in the Return of Optimus Prime, a truce with Galvatron and the Decepticons, and the temporary depletion of the Autobot Matrix of Leadership. The events described here took place in the G1 episode The Return of Optimus Prime.

The Hate Plague is a seemingly non-sentient life form that breeds contempt, violence and hatred in any living creature it comes in contact with, including mechanical and organic life. An infected individual can be identified by a dark red glow. Physical contact is required to contract it, except in unusual situations where the atmospheric density of the spores results in a critical concentration. In and of itself it does not appear to be fatal; however, the resulting behavior increases the possibility of a violent death. It is unknown if the spore plague was engineered to use violence as a method of propagation. The spores are immune to all known forms of radiation, including heat and gravity, however certain metals can contain (and shield individuals from) the spores.

It was released at least one time in the (pre Cybertron civil war) past, and a scientist was able to contain the spores and shoot them onto the surface of a distant star.

The spores were accidentally discovered by Dr. Jessica Morgan and her partner, Gregory while testing a heat and radiation resistant alloy on their ship by taking it close to the surface of a star going nova. (This is also the expedition that recovered Optimus Prime's stasis-locked body.) The spores covered the hull, but could not penetrate. They lay dormant until introduced to a living being, the Earth rat, in an aerosol form. At this time, the Decepticons attacked the laboratory to acquire the radiation-resistant alloy. Dr. Morgan was injured in the attack, losing the function of her legs. Autobots fitted her with an exoskeleton that allowed her to walk, but either through prejudice or slight contact with the spores her father was furious.

After attempting to revive Optimus Prime on their own and failing, Dr. Morgan (Jessica's father) and Gregory devised a trap for the Autobots. They placed Optimus's body in a sealed room where Autobots would attempt to retrieve him. Once they entered, they released the spores in aerosol form. The contagion spread from there all across Earth. Members of the Earth Defense Force and other Transformers capable of offworld flight eventually spread the spores to other worlds; a galactic epidemic was in progress.

Sky Lynx, one of the few Transformers able to escape infection and the only one currently capable of space flight was given orders from Rodimus Prime to find a Quintesson who may be able to revive Optimus Prime (as they had done it before, in the episode Dark Awakening). After finding a Quintesson, Optimus was successfully revived and a plan devised to recover the Matrix of leadership from the now-infected Rodimus Prime. In order to make contact with Rodimus, he coated himself with the alloy created by Dr. Morgan that he acquired on the planet Chaar with the assistance of Galvatron.

Once in possession of the Matrix, Optimus Prime traveled into it to find out as much as he could about the plague; After finding that a construct of the Matrix had knowledge of it, Optimus reawakened and released the essence of the Matrix. Through some unknown means, the Matrix was able to cure those infected, however, at cost - for a period of time; the Matrix was rendered unusable for unknown reasons.

The current status of the spores is unknown; It is possible some survived the Matrix blast and are still in space.

Notes

The only three characters in the episode Return of Optimus Prime who definitely never get infected by the Hate Plague are Optimus Prime himself, Metroplex, and the Quintesson that Sky Lynx brough to Earth.

It is rumoured that this plague was at least partly responsible for inspiring a similar Hate Plague in the movie "28 Days Later".