He cautiously made his way through the ruins. He had a name, but it had long since been forgotten. His name was now a word that had been written under a drawing in the margin of a journal he didn't remember keeping. His life had become one of service to the Foundation. Now the Foundation was no more, and he had returned to the site of his greatest failure.
Just what was the agent's greatest failure, he wasn't entirely sure. Perhaps it had been leaving the site without making sure everyone understood his instructions. Perhaps it had been failing to ensure that the robots had all of their moving parts protected. Perhaps it had been allowing his paranoia that the containment procedures on 359 weren't sufficient, and he had to see for himself, to get the better of him, which had been his reason for leaving in the first place. But whatever it was, within a day of his leaving the site, there was no longer a site to return to.
The news had come from one of the Level 1 personnel who arrived at 359's roost. The vine had somehow hitched a ride on one of the robots, he claimed, and had killed anyone who saw it. People had been sent to the lab with flamethrowers to attempt to contain it with minimal collateral damage, but to no avail. The more people it killed, the faster it spread. By the time the situation had reached the point where activating the on-site warhead would have been a viable option, anyone who had the security clearance to do so was already dead.
The agent had called in an airstrike on the former site, but the vine had already spread far beyond the site by the time it was cleared. Within a week, the entire American Midwest was overgrown.
He and the remaining survivors had erected a shelter, a massive steel dome with a glass roof to let sunlight in. He knew the plant couldn't put down roots in metal or glass, and the glass was too high for any vine to reach without roots for support. He had thought they would be safe in there. He had forgotten the ingenuity of the plant.
He had lost track of the time the survivors had spent inside the dome when the attack came. The vines had crept over the glass window and smashed it with the rocks held in their roots. Next had come the Great Rain of Mice. Dead mice began to fall through the broken skylight, erupting with vines the instant they hit the ground. The survivors had been caught completely off-guard. Within hours, the dome had been completely overrun.
So now, dressed in a thermal insulation suit specifically designed to shield his heat signature from the plant, he returned to where it all began. He wanted to understand where everything had gone wrong. He had already seen that the plant had stacked various porous objects against the dome to reach the skylight.
As he climbed over the numerous skeletons, humans and otherwise, entwined in the mass of vines, he saw something sitting in the middle of the room. It was one of the robots that had been used to maintain the plant after Incident 307 had killed a D-class personnel. One of its arms had long since rusted and fallen off. As he approached, he could see a plant growing out of it, with its roots set into the rubber casing on one of its hydraulic tubes.
He prepared to turn back, when something at the other end of the room caught his eye. It appeared to be a light, but the sun had set hours ago. Against his better judgment, he made his way through the vine-strewn door. He immediately recognized the room he was in. It was the plant's containment cell, and the light, which was somehow still lit, was the hydroponic chamber where the original specimen had been contained. But now, there was something different underneath it.
The hydroponic station had been replaced by a table, with several glass terrariums on it. Inside each terrarium was a sizable colony of mice. As he watched, a vine snaked forward, lifted the lid off of one of the terrariums, and touched one of the mice, which froze on the spot. The vine wrapped around the mouse and removed it from the terrarium. So that's how it's survived all this time, he thought. The damn thing is farming hosts!
He turned to leave, but felt something tug at his leg. One of the seams on his suit had become caught on a thorn. Before he could decide the best way to disengage himself, the vine began to move towards the mice, pulling the seam out of the suit completely.
Instantly, the vines homed in on his heat signature and grabbed the suit with their thorns. He could hear them tearing at his clothes, as a particularly large vine wrapped around each limb and forced him to his knees. As he looked up, a single vine crept up to his face.
It was a plant. It didn't have a mouth. It didn't have a face. It didn't even have a head. And yet, for just a second, he almost swore it was grinning at him.