For the last fifty years, the ageless Dusk Eclipse has been combing the world at large, living on her own, searching for her closest "relative" and source of job: Project Shadow, the Ultimate Life Form. You see, Professor Gerald, all those years ago, sensed how dangerous life would be for Project Shadow, thus he created Dusk Eclipse, a specialized guardian for the Ultimate Life Form. Dusk kept her job from Shadow a secret on the ARK, going to such lengths to conceal herself that Shadow was oblivious to her existance.
On the fatal day the ARK was shut down, Dusk lost track of Shadow in the crowd of people pushing past her to get off the ARK. He had taken the Professors granddaughter--Maria--by the hand and tried to lead her to safety before Maria could alert Dusk. With no time, Maria had sent Shadow rocketing to Earth only seconds before Dusk burst into the room. Dusk had been quick to leave the ARK, but she knew she would never find Shadow again...
All this is only a mere highlight of Dusk's mysterious past, and even amidst Dusk's futile attempts to rediscover the Ultimate Life Form she struggles everday to remember exactly what happened on the ARK that day, and find out what fuels her terrible phobias, thoughts, and secret desires...
But everything changes when the fully grown grandson of Professor Gerald discovers the other ultimate project the Professor had been working on the--the deadly Eclipse Canon, certain to bring a doomsday to the defenseless planet earth. Doom is certain, unless the citizens of earth bow down to the evil genius, and accept him a the ruler of the planet. But even Dr. Eggman isn't prepared for the worlds fastest hedgehog, aided by a two-tailed fox, a spunky pink hedgehog with a big hammer and a fiery love for the blue blur, and a powerful red echidna with more on his mind than just saving the world to step in and save the day. And what these heroes don't expect is a stowaway on the rocket up to the ARK, formally known as Dusk Eclipse, who knows that the Canon could only have been activated with the help of Shadow, and who needs to meet up with him again...
And even as Sonic the Hedgehog, Miles "Tails" Prower, Amy Rose and Knuckles the Echidna fight for the world, a new fiery passion is growing, laced with fear, anxiety, uncertainty, and a terrible internal struggle ending with an emotionally explosive climax...
Deadly secrets will be brought to the surface, the truth about what happened on the ARK will be revealed, hearts will plummet, destruction will ensue... and it will be the worst 24 hours of everyone's lives.