Infinite Staircase

By all appearances it is a typical staircase in a stairwell with a flight of stairs followed by a landing followed by another flight adjacent and above the first.

When climbers enter on the first floor the elevator descends into the basement at the same rate as the climbers ascend. Once they reach the landing they turn the blind corner into the adjacent elevator that is still on the first floor and climb the stairs in that one.

As they climb that elevator descends at the same rate as they ascend. When they reach the top of the stairs they are still on the ground floor, and the first elevator they travelled in has moved into position as they turn the corner on the landing. Thinking they have reached the second floor they continue their upward trek without realizing they have not moved.

The climbers grow weary as they lose count of the flights of stairs behind them as the monotonous droning of a bank of elevators can be heard from somewhere nearby. The doors on each of the landings are locked and the floors are unmarked. They become disoriented and begin to panic as the boxes they have been hired to carry grow heavier and begin to slip from their sweating palms.

They begin to wonder how tall the building they are in is, and regret riding in back of the windowless cube van with the boxes. When they had arrived in the parking garage the only instructions were to carry the boxes to the top floor.

Needless to say they eventually discover, to their horror, the boxes contain scale models of the staircase, complete with miniature climbers staring into opened boxes.