A/N: In my world, accidental magic occurs in the form of regular spells but performed wandlessly. ie: when Harry blew up his Aunt that was really an engorgement charm. I know this does not follow with the books, but it is my interpretation. The funny part is, I don't even like mushrooms.
Spinning trees. Many many spinning trees that made his head hurt. They were pine, and was that sap dripping onto his nose? Harry rushed into a sitting position and regretted the fast movement immediately, his head pounding with enough force to crush the very rock he was sitting on.
Wait, rock? Not stone? He looked down and found that he was indeed on a large boulder, not the rough cobblestones that made up the floor of Azkaban prison. His heart filled with joy, or at least as much joy can come when your head is pounding. He was free, and somewhere in the woods, where they had boulders and pine trees. He blinked a couple times and managed to somewhat clear his vision. It seemed that he had lost his glasses somewhere along the trip and his vision remained clouded despite his blinking.
He stood up, careful to feel his way around and discovered that he was at the base of a mountain, a rather large one at that. It seems that it is the nature of humans to climb things even when there is no logical reason to do so, perhaps to see more of the surrounding terrain (as the phenomena is often justified by), but more likely it is so that we can feel as if we have accomplished something. Thus in Harry's mind he had to accomplish something now that he was out of jail, and set out climbing the mountain. Wandless and nearly sightless, the fledgling wizard set out climbing.
He stumbled often at first, earning himself several skinned and bloody knees, but after a short while of climbing, something changed. He did not regain his eyesight, it was different. He just knew where the boulders were; where the roots were; where the nesting birds were. The mountain became alive to him and he could feel it inside of him, a compass guiding his actions.
Eventually he crested a hill and found that he had nearly reached the peak. Looking back he found that he could finally survey his surroundings, if he had had his eyesight. As it was all he saw was a lush blur of greens and blues. He sighed and turned around. What he felt to be before him was interesting, very interesting.
The same awareness that aided his passage up the rocky mountain was now alerting him that before him was a deep fissure in the rock which extended upwards and was the peak of the mountain. The fissure itself was narrow in width but rose to nearly the entire height of the crowning rock of the mountain: a good thirty to forty feet. He squared his shoulders and stepped inside.
He was immediately rendered breathless as he entered the cavern. It was not the physical appearance of the cavern, nor was it filled with anything rare or valuable, but it was as if the air were alive. He felt himself grow breathless and energized, despite still feeling the aftereffects of his long climb. He glanced around, expecting to at any moment find some incredible magical device causing this feeling, to no avail. The cavern itself was rather barren in fact, perhaps 15 feet deep and 10 feet high. It was cozy but not snug, roomy but not...cavernous bad joke, I'm sorry. It felt like home, in a strange sense.
He sighed and sat down on the moss covered floor, sinking into the spongy plant. He sighed as the pressure was released from his tired feet, making them feel weightless. His stomach gurgled. He looked down and, while not seeing any physical change in his stomach, felt a pang of hunger appear inside of him. He sighed again and stood again, putting the weight again on his tired feet, and headed out. Revitalized by the energies of his cavern, he set out in search of food, not really knowing what to look for.
He set out walking on a game trail, most likely made by a deer or large creature of the sort, using his new type of feeling to search around him. He found that something had to be in his line of sight for him to 'feel' its presence, and proceeded to swing his head back and forth in an attempt to sense as much as possible. He just ended up dizzy and decided to concentrate on his left side on the way out, and the right side on the way back in. After a short time walking he discovered a patch of mushrooms and decided to leave them, lest they be poisonous. He moved on, not really finding anything of interest.
A flash of movement permeated his feeling and he threw up his hands. It were as if he was hit square in the chest with a sheet of glass the size of his body, and he was tossed backwards. Slow to get up, he shook his head to clear it and looked for what had hit him. He found a tree had fallen on him from his side. This in itself was not the surprising bit though: it had fallen on top of him but the section set to pummel him had been knocked out of the trunk, as if by a giant hammer, and lay strewn in small chunks on the ground around him.
He thanked all he had ever known that he had chosen that moment to do some accidental magic, though he wasn't really sure what spell he had done. A bludgeoning spell surely wouldn't have taken out so large a chunk of the massive tree. he walked around the tree, inspecting it, and was rewarded with a rare treat. He recognized something growing on the bark he had never tasted himself, but saw routinely in his youth. When serving his relatives, he often was required to grill shiitake mushrooms, and had always wanted to try one. It seemed now was his chance, as he had encountered a tree covered with them.
He picked off as many as would fit in the pockets of his tattered prison robes and headed back, not bothering to scan the other side for food. In his excitement over the mushrooms he had completely forgotten to think what spell he had used.
When he returned to his cave, he sank back gratefully into the moss carpeting and spent 15 minutes or so in perfect contentment munching away on his mushrooms. When he finished he sat there thinking about his predicament. He would have to look around tomorrow to see where he really was. But now, sitting there on the comfortable moss, he felt happy knowing he was well fed and comfortable. He felt the days events catching up to him as the fiery sun sank below the horizon and his eyelids drooped. He lay down on the moss, curling into a peaceful ball and fell asleep.