Gabriel looked with concern at the sapling in the corner. Its silver-gray leaves drooped and the plant, not more than four feet tall, projected an overall air of forlornness. Behind the ornate pot holding the plant the transparent panes of a wide bay window showed a murky red sky and rolling brown dunes denuded of vegetation, numbing in monotony. The dullness of the scene had no effect on Gabriel. His whole concern was focused on the plant before him.
Reaching out, he touched one of the leaves with his thumb and forefinger. It was the most delicate of touches but even that slight contact seemed too much for the sapling. It trembled and the leaf came away in his hand, leaving a stark white patch to mark the spot where it had detached from the trunk.
Gabriel inhaled sharply in dismay, examining the leaf in his hand. The top of the leaf was still a handsome silver gray but the underside showed mottled patches of brown and yellow and a spidery pattern of cracks covered the surface like a fine lattice. Even as he watched, the little tree seemed to sway, although no breeze stirred inside the building. Another of the lower leaves detached itself and floated down to join a small group of its fellows in the base of the pot.
Clutching the leaf in his hand Gabriel ran back up the long avenue leading back to his central office from this remote alcove on the edge of the building.
The office was hexagonal and glass-walled, providing a panoramic view of the interior of the building, which was large. From the central perspective, the six sides of the building were clearly evident, a macroscopic version of the office itself. Inside, machines and displays stood banked against the clear walls except for a small curtained alcove providing the only privacy in the entire building. The alcove contained Gabriel’s private quarters, although privacy never concerned him these days. Gabriel was the only occupant of the transparent building.
Hastily he dropped the leaf he was holding into the receptacle of a quietly humming machine and pressed some buttons. The leaf disappeared inside and the machine made quiet regular sounds as it analyzed its input. Less than a minute later a small screen popped up and data began to scroll down its surface. The receptacle popped open again but there was no sign of the leaf. Gabriel glanced quickly at the display and his shoulders sagged visibly.
Two days, he thought. That was all the time the sapling had left. The deterioration was irreversible and permanent. The tree was dying. Sadly he walked back out of the office and onto the wide plaza with its six broad avenues branching out precisely to the six sides of the building. Retracing his steps to the sapling, he stood looking at it, knowing he would have to take it out of the pot and destroy it before it infected any of the other plants nearby. But not yet. There were still two days and he could enjoy its company a little while longer.
Stepping to the clear wall, he pressed his face to the surface and looked outside. The building stood on a bare hilltop whose gentle slopes lead down to a shallow valley. The slopes were bare brown and dusty, the valley a continuation of the same. Beyond, other small hills rose up around him, similarly denuded and desolate, an endless procession stretching out into the distance. Gabriel knew that beyond the hills lay a great plain, equally dry and desolate, scoured by fierce winds that were gradually eroding the hills into dust. A world of perpetual dusk. He had not been outside in more than a century. There was nothing out there anymore. The machines that kept his building alive maintained him too, his circuits recharged and replenished as he rested in the nothing state he had come to call sleep.
But he never really slept. The term was a throwback to his long dead creators who had made him for a very specific purpose. He needed to stay vigilant. That was his imperative. He was the Keeper. The Keeper of the last greenhouse in the world.