Swapping: Fantasy

Escape was rumored to be impossible. Looking around her at the heavy ranks of guards and the thick stone walls, she could believe it. She shivered. It was a good thing that her plan didn't require escape--just a little creative cell-swapping. All she needed was to be replaced by one of the other horribly ill inmates who'd been here a very long time and were just about ready to die. They would probably not mind her proposed fate, which she objected to quite vehemently. There was only one time when the swap could even take place. As part of their "humane treatment" of the prisoners, there was a designated half-hour of exercise in which all the prisoners were shuffled into a small courtyard with very, very high walls. If you craned your neck, you could see a narrow square of sky high above. It was--

Inspiration: "Escape From Meridell Castle"
Story Potential: Low.
Notes: Boo-riing.