Mystery: Ultimate Darkness

Mystery: Ultimate Darkness was a 2011 Sonic the Hedgehog "script fic" fanfiction written by Ryan Nurse and Aaron Middleton. While it was the third of Nurse's Mystery the Hedgehog fanfictions, it was the only one to be written in its entirety. Although the final product was of poor quality, it was significant for numerous reasons: it was the first of Nurse's projects in which he actively collaborated with another person, the first to achieve completion, and the first to receive a public release.

Ultimate Darkness was written between October 2010 and May 2011, while Nurse and Middleton were in their final year of secondary school. It was published on DeviantArt in eleven instalments between 14 May and 22 August 2011, with a twelfth "prologue" instalment published on 7 October without Middleton's input. Though both parties had sequels planned, these were cancelled in August 2014 after the Mystery franchise was turned into Project Nero.

Synopsis
An unspecified number of years in the future, Mobius has been completely enslaved by an alien overlord called The Puppeteer, and has become a desolate wasteland. The High Council of Time Travelers, a body set up to regulate the use of time travel, sends a hedgehog named Adachi back to the time of the Puppeteer's arrival on Mobius, in order to gather the Golden Allience, a legendary group of warriors, to prevent the villain's rise to power. Arriving in present-day Station Square, Adachi swiftly assembles the team: swordfighter Mystery, alcoholic gunfighter Alexis, mechanic Forza, modified Shadow Android Lotus, exotic dancer Solstice, mute teenage prodigy Melody, and cryokinetic hippie Ripple. When the Puppeteer makes his first attack at a demolition derby, the group gathers and manages to fend him off.

After fending off an attack from Dr. Eggman, in an attempt to reclaim Lotus, and helping to topple an island dictatorship, the gang turn their attentions to gathering the seven Chaos Emeralds in order to gain enough power to defeat the Puppeteer. As they gather more Emeralds, each team member - excluding Lotus - unlocks their own super-form. Meanwhile, Alexis finds herself falling in love with Mystery, but gains an intense rivalry with Adachi that culminates in a violent, yet inconclusive battle.

Finally, with all seven Chaos Emeralds in their possession, the team gathers at the dockyard for the final battle against the Puppeteer. After a long, difficult battle, Adachi sacrifices himself to kill the Puppeteer, but is then revealed to have left a holographic message for the team, along with presents from the future for each member. Melody, who had been cautious regarding the idea of time travel, is revealed to have been the founder of the High Council who sent Adachi back in the first place.

Characters

 * Mystery the Hedgehog: The titular character, and de facto leader of the Golden Alliance. A skilled swordsman who can also run up walls.
 * Adachi the Hedgehog: A powerful hedgehog sent back in time to assemble the Golden Alliance and prevent the Puppeteer's rise to power.
 * Alexis the Hybrid: An alcoholic, motorcycle-riding outlaw who fights uses twin SMGs. Over the course of the series, she comes to fall in love with Mystery and hate Adachi.
 * Solstice the Fox: A seductive woman and friend of Melody's who is able to fly short distances.
 * Melody Mongoose: A shy girl who became permanently mute as a result of childhood trauma.
 * Lotus the Android: A damaged Shadow Android repaired and rebuilt by Lotus. He has the power to interface with other machines.
 * Forza the Fox: A skilled mechanic and friend of Mystery's.
 * Ripple the Porcupine: A laid-back hippie who can freeze large areas using his mystical "Ice Chips".
 * The Puppeteer: A villainous alien who wishes to conquer Mobius. He is able to summon dark creatures and hypnotize others.

Development
In 2010, Nurse began significantly re-developing his Sonic fancharacters, giving them more realistic abilities and backstories and diversifying their appearances. This was in preparation for his planned reboot Mystery: The Legion (later Mystery: The Alliance, and ultimately turned into Project Nero), which Nurse intended to be the "crown jewel" of his fanfictions. Ultimate Darkness was Middleton's idea, and Nurse agreed to start writing the series with him in October 2010 as a separate spin-off series.

The duo wrote twelve episodes, with Nurse recycling several plot ideas from his previous unwritten fanfictions. Episode 2, "The Darkness Begins", was adapted almost verbatim from the Adventures of Mystery the Hedgehog episode "Demolition Derby", while "The Unexpected Forms", in which Melody first gains her super-form, was an idea Nurse had created but not previously used.

Episodes 8 and 9 were mostly dedicated to Alexis' backstory, including the revelation that she had unwittingly killed her own parents. The episodes depicted Adachi traveling back in time and preventing both the aforementioned murders and also the car crash that had killed Melody's parents, returning her voice to her. Nurse ultimately decided to excise these plot elements from Ultimate Darkness, the former in order to save the revelation for Alliance, and the latter due to his personal dislike of it. The two episodes were thus cut from the show, with the other important scenes from them hastily assembled into an "Episode 7.5" to fill the gap. The prequel "Episode 0" was written by Nurse two months after the final instalment had been published, filling a few remaining plot holes and padding the series back out to its original twelve-episode length.

Cancelled sequels
After Ultimate Darkness had been completed, Middleton intended to write a second season with Nurse. As well as a new villain, this would have introduced Rocket, another time-travelling hero, as well as Genevieve, an apprentice of Mystery's. The second season would also have resolved the plot thread of Mystery's arranged marriage from Season 1. The pair wrote one episode of the new season, but it was cancelled when the pair left secondary school and went their separate ways.

In the following years, Nurse began to play his own, separate sequel. Subtitled Vast Darkness, it would have featured the Golden Alliance boarding a spaceship named the Gaia, which had travelled back in time 100 years in order to stop an alien armada before it could destroy Mobius. Ultimately, this too was scrapped after the Mystery franchise was folded into Project Nero.

List of episodes
[Note: The cancellation of episodes 8 and 9 let to episodes 10, 11, and 12 being published as 8, 9, and 10 respectively]