AN: Sorry for my English. It's the first time I try to translate my stories. Please tel me if I write something in the wrong way, so I can correct it. The story is freerly inspired by videogames and comics of Sonic the Hedgehog and Knuckles the Echidna. All the original character are property of Sega and Archie Comics.

Chapter 1: the Future

The city towers stood above the forest and cherry trees in bloom. The tower's pearl white reflected the sun's rays, and made them shine against the clear sky. All was calm, peace. Nature and technology in perfect balance in the simple perfection of an instant. Then, a shadow stretched over the trees and overtook them. The leaves fell, leaving only a woodland of black poles. The shadow climbed the buildings to the top and lost itself in a crimson sky. Here, it took on a form, a face emerged, nothing more than a mask bristling with fangs.

It's lost ... All is lost ...

Silver opened his eyes and stepped back. Around him, the warmth of the fireplace and the silence broken only by his cracklings. One hand searched for the armchair and the other for his aching head. He sat with a sigh.

- Grandpa?

He winced and turned back as far as the armchair allowed. He knew it wouldn't help, but old habits die hard - Tera? Shouldn't you be in bed?

- I couldn't sleep.

He heard her approach, a lively and light patter that he had learned to love. He picked her up.

- Can you tell me about Sonic and Tails again?

He smiled - Tomorrow, honey. Now you must sleep.

- But I'm not sleepy!

-Shh. I'm sure your parents are already sleeping and if they wake up we'll both be in trouble. - he tickled her nose. Feeling the smaller hands tighten his fingers warmed his heart more than any fire. - Just one, and you promise me to go to sleep after the story.

Four hundred years.

Four hundred years beyond the future.

It's difficult to believe in the unrelenting passage of time which, like a river, erodes reality piece by piece, until there remains only dust of what was.

Silver had witnessed erosion longer than any other living thing but he didn't considered himself lucky: he had a taste of immortality, with all its bad and good things. He was happy to be the middle way.

Sonic, Tails and Amy had long since died, after countless adventures. Silver liked to think they're all together, happy in some wonderful place in skies. However, for Shadow and Knuckles, the matter was different.

They would stay with him and after him. They would have remained until the end of the world, Sun's collapse, even to the end of the universe as far as he knew. Maybe even after, if an after existed.

One was the perfect life form, and in designing it Gerald gave him a body capable ti defeat death, through a process of rapid tissue and energy regeneration. Shadow didn't age. And he would never die of old age.

The other was the eternal guardian of the Master Emerald, the last and irreplaceable bulwark of a defense as old as Mobius.

The energy of the Master Emerald kept him alive, gave him strength, kept him young and, if the emerald was destroyed, he took refuge in him making the guardian more powerful. Silver could only imagine how old the echidna was and how much he had seen in his life. He would live as a guardian of ancestral energy until someone more powerful killed him.

However, Silver wasn't so sure that the echidna could be killed: the Emerald would not allow the last guardian to die. Many would have found this an amazing situation, but for Silver was terrible: the echidna was only a slave of an ancient and greate power, that bound him for life and death.

Sonic left quietly in his bed, smiling, tearing a promise to th two: protect the world after him, and help those who want to protect it.

After his death, Knuckles retired to Angel Island, closing in silent mourning and refusing any contact with the mainland, except for Shadow. The dark hedgehog regularly visited the island, often stopping for weeks, before returning to the city. He lived as if immortality didn't matter, creating bonds that once broken by time left a painful void in his heart. On those occasions he went to Knuckles.

Together with a gift and a curse at the same time, they supported each other developing a powerful bond of friendship, firm as a diamond chain. Something so intimate and deep that Shadow could only identify with his bond with Maria. They had lived together, laughing and crying, until Silver was born, then for another four hundred years, and Silver knew they would go on until death caught one of them.

Stronger bond, greater pain.