Long ago I met a man who offered me the Universe, all of time and space and everything that means.

And I went.

He has shown me wonders of which the human race can never dream, we have travelled to the farthest reaches of the Galaxy and watched the Universe die. I have seen the birth of our Sun, and journeyed through the vastest of empires devastated by the terrors of interstellar war. I have seen the final days of our race, and known the fates of every being.

I have seen all this with this one man, greatest and wisest and best of men. I have seen him in all his glory, the power he wields and the joy in his heart when he gives a single being just one more day of life. I have watched him as he carries out his eternal task, legacy of long-ago rebellion, to watch over history and guide the ages down their predestined path.

I have seen all this, with this one man, and known that I will never have to leave him.

Because he knows.

He knows how it feels, to have the Universe at your fingertips, to be able to reach out to the furthest depths of time and space and know no limitations. To have this, the ultimate freedom, and have it stripped away by those who say, this is for your own protection.

Those who say, you are safer here, this is your home and we need your talents here. Your people need your knowledge, so do not waste it on those who will never know what you have done for them.

Come home, and we will keep you safe here, in this shadow prison with roof and floor, four obdurate walls and no door.

He knows this, this living death, and so I know that he, wisest and greatest and staunchest of friends, will never leave me.

But I am wrong.

Because he has left me here, saying I have the rest of my life before me, and the will and the way to make it the best it can be. That he cannot take this away from me, just so he won't be alone.

And now we both are.

Now I walk these earthly ways, trapped in time amongst those who will never see the stars. Now I watch over them, as he watched over me. Watching for the coming of alien menace beyond the stars.

Watching.

Waiting.

Dreading.

Hoping.

Hoping beyond hope that when the invaders come he will follow, guaranteeing the safety of this world as he has done so many times before. Hoping that just once more we will be joined in common purpose.

And as I watch and wait I try to help, try to make this tragic world a little better.

But how can I, without him? When I have seen the wonders made by his own hand, how can I hope to compare? How can I go on, dreaming of another life?

Yet I must, for this is the task he has set me, and I will fulfil it to the day I die.

So I trudge each day along the so well-trodden ways, out on the journey so many others make. This dirty struggle to survive, shrouded in the glamour of civilization's greatest abomination – progress. Day after day, this is my life.

But on this, the most ordinary of days among a million, I hear the sound that for so long I have been waiting. This is the sound of the Hyperspace Vortex, the scream of space-time itself ripped asunder.

This is the sound that heralds his return.

So now I race out the door and down the drive, along the many, endless streets that stretch unending towards the park where we first met.

And he's standing there, now, waiting for me to join him once again.

I cast my eyes to the living craft beside him that has carried us on so many journeys. To me, it is magic, to him, science. A memory rises, the words of Sir Arthur, that any sufficiently advanced technology is indistinguishable from magic. Clarke was one among a thousand men that I have known yet who lived years before my birth. Countless more there are whose fates I know though have not yet been born.

It is this thought that stops me cold. The people that I now count as friends, travellers and voyagers who saved me from the depths of my despair – can I leave my debts to them unfulfilled, return to the stars and learn of their deaths?

I cannot meet his gaze, for once I do, I know, there will be no turning back.

When I first left this planet I was alone and friendless. Unchained, unbound, I had no obligations to tie me to this Earth. But he opened my eyes, showed me the wonders of humanity and the joys of this planet that only now do I call home. There are others, I have found, who have also seen the stars. We alone protect this Earth when he, unknowingly, cannot. I cannot leave them, they who forged a window in the cage of my despair. I cannot open the door that will free me from this shadow prison.

I cannot speak to tell him this. Sorrow for sights I will never see, people I will never meet closes my throat. All I can do is look into his eyes, and know that the regret in mine will tell him my mind.

I meet his gaze, now, and remember.

I remember the burning sorrow of his eyes when he, the Oncoming Storm, cannot save a life.

I remember the frozen fury of his heart when he, Destroyer of Worlds, is forced to choose – a life for a family, a people for a world, a friend for the Universe.

I remember the black abyss of his mind when he, Bringer of Darkness, watches oblivious joy flee and cruel memory return.

I remember the ceaseless anguish of his soul when he remembers that he, the Lonely God, greatest and last of the eldest of races, is alone.

I remember these words, as clear as the day I saw them first spoken. He who saves a single life saves the world entire.

Never have they been more true.

I remember, now, and know I cannot leave him.

How can I let him go on alone, and still expect him to save this world? How can I refuse the call of my heart, chain myself to this flightless planet and never meet again my friends among the stars? How can I walk away, when my greatest debt is to him, he who opened my soul and showed me eternity?

Quite simply, I cannot.

And so I take his hand, cross the threshold of his living ship, and lo! my debt is repaid.

'Can you imagine silver leaves waving above a pool of liquid gold containing singing fishes? Twin suns that circle and fall in a rainbow heaven? Another world in another sky? If you come with me, I will show you this – and it will be, I promise you, the dullest part of it all. Come with me and you will see wonders that no human has ever dreamed possible. Or stay behind, and regret your staying until the day you die.'