Sally had gone to bed ordinarily the night before, and when she woke up, the ladder was there.
It shone a silvery grey in the morning light, without any sign of dirt, rust, or tarnish.
It was about a metre wide, with rungs spaced evenly at intervals of roughly 30 centimeters.
And - most strikingly - it went on forever.
Sally stood in her garden at the foot of the ladder.
She really didn't have much else to do today.
She began to climb.
Sally estimated she was a few tens of metres off the ground.
Maybe that doesn't sound like much, but you tend to judge vertical distances different from horizontal ones.
Sally was glad she didn't fear heights.
Looking down, Sally was surprised to see a rough crowd of people gathered in her garden and in the neighboring alleyway.
One of them seemed to be wearing an official uniform - police, maybe.
She couldn't really tell.
Honestly, she was a little surprised there weren't more people there.
The sudden overnight appearance of an apparently infinite vertical ladder, she thought, is surely unusual enough to attract a variety of onlookers.
Why were there only 5 or 6 people down there?
The train of thought petered out without any clear conclusion.
Sally dismissed it, and continued upwards.
Sally wasn't sure how high she was, but she could see most of the city spread out below her.
She wished she'd worn more before setting off.
But she'd already got so far, and didn't want to waste the effort.
Really, Sally mused, it was nice to have a task at hand that was this clear and simple.
It was a welcome change from the complexity and uncertainty of her everyday life.
And infinite, too! you never need to worry about what to do next, if what you're doing right now will last forever.
One hand above the next, above the next, above the next.
But maybe it wasn't infinite?
Sally was far above the clouds now.
They formed a soft, white, inviting carpet in the otherwise empty blue sky.
Straining her neck to look upwards had been uncomfortable, so for a while she had been looking at the rungs in front of her, just focusing on putting one hand above the other.
But now as she took a second to catch her breath, she looked up again.
The ladder no longer seemed to stretch onward to an infinite zenith: Sally could see a rectangular platform, just visible, silhouetted against the sky.
Maybe a few hundred rungs above Sally's present position.
For the first time that day, Sally felt uneasy.
Was that a human figure standing on the platform?
Spurred on by her discomfort, Sally quickened her upwards pace.
5 rungs below the platform.
It was about 5 metres wide and about 10 metres long, with the long side pointing away from the ladder.
And it was shiny, like a single enormous bathroom tile.
If there really had been a person on top of it, Sally could no longer see them from her present angle.
She supposed she'd get a better look once she was on top.
Triumphantly and expectantly, Sally reached up and grabbed the final rung at the top of the ladder.
Unfortunately for Sally, the top rung was not a rung at all, but a razor-sharp knife blade, and all her fingers were severed immediately.
Streams of blood formed great arcs in the cold air as Sally fell backwards, chaotically, head-over-heels, all the way down to the ground, and died instantly.
The end.