There are many stories about people trapped in elevators, sure, but what about escalators? Story is complete as is, see Life in the Tesseract, for the sequel, and Life, Liberty, and the Pursuit of Justice for the finale.
The conclusion of the Undiscovered Countries trilogy. The horndogs will have to forgive me on this one, for the lack of triple-x narration. This story is a serious attempt to explore issues of terrorism, within a sci/fi plotline.