Gerald got into it for historical reasons. Back before the Baby Bust, back when the suburbs were swarming with climate-altering automobiles, there used to be this thing called "urban exploring". People would find buildings, infrastructure tunnels, all sorts of locations that were abandoned. They would sneak in, photograph them, and research their history.
Gerald did that now, except with the abandoned suburbs. He joked that the advantage of his variation on the hobby was that if anyone scary were around, you could spot them and bike away long before they had a chance to get close to you. Once you cleared the gate in the Etobicoke or East York walls, you could see for kilometres and kilometres.
To the southwest he found a cairn, telling the story of a town that had once stood where now there were only hectares of rotting asphalt. The town had been split in two when the highway had been built, and had died like any other large organism would when it was bisected. Now the highway and the giant carpool parking lot had been abandoned too.
Gerald turned in a slow circle, straining to pick up any signs of currently-used civilisation. Nothing. He saw something move by a clump of bushes on the other side of the old highway, but figured it was just a bird or a raccoon.
Once winter came he stuck within the city walls; the coyote and wolf populations had somehow bounced back more quickly than the deer, and it wasn't safe to venture out that far with so little sunlight in a given day. Besides, even the winter treads on his bike tires would skid badly if he hit a patch of black ice.
There was plenty to explore even within the city limits, though. Like the dead carpool lot and highway that were paved over the dead town, Toronto had layers of abandonment within it. There were the high-rise condo towers with the top ten or fifteen stories closed off. If you could figure a way in, you could see how people lived in the early decades of the century. Some of the units still had their major appliances in them, and many of the floors still had electricity running. It was proof of how big the Bust had been that Gerald had discovered so little evidence of squatting.
There was a spit of land out on the lake. In pre-Bust times it had been created by dumping all the soil dug out of skyscraper foundations. Far from being the industrial wasteland it should have been, the city had declared it a bird sanctuary and paved cycling paths through it. At the very end of the spit was a small, still-operating automated lighthouse.
Gerald liked riding his bike out there. On a still day the only sounds would be the hum of his tires on the pavement and the calls of the birds as they settled into the trees. Often building debris would get mixed in with the dirt and the gravel. He had found everything from late twentieth-century beer advertisements to bricks with dates from the late eighteenth century imprinted on them. The city was older than that, he knew, but before most things had been made out of wood, so the evidence was scarce and hard to recognise.
It was a very cold, dry, bright day when he found the stairs. They were just sitting there, in a wide flat part of the spit that hadn't grown in with grass and trees yet. He liked how they looked in the harsh midday light, and got off his bike to take a photo.
When he got closer he discovered that there were footprints on the three stairtreads, fresh and sharp in the cement dust. He took photos until he was satisfied he had the shot he wanted, then cycled home.
It was only when he got home and saw the photo on his larger video screen that he noticed that there was only one set of footprints, going up, with no pair at the top of the stairs to indicate the person had stood there. Whoever had made them had ascended, and then, by all evidence, simply climbed into the air.