Once upon a time there was a boy who lived on a dam. The waters behind stretched as far as he'd ever been able to see and the land beyond always looked so beautiful from his lofty perch. The dam, so far as he'd been able to determine, was all that stood between the frothy waters above and the blissful serenity below.
The boy never had time to travel very far to sea or down to the valley below because the dam was constantly popping leaks. Every day, he'd get up and prepare some kind of quick fix so that he could keep the people safe below. Sometimes he'd get a day or two where there was only a minor problem, but every day there was an issue requiring immediate attention. He couldn't leave his station or the lands were doomed.
The dam helped, in its own way. Whenever the boy needed supplies, he'd find them in an open storage area near where they were needed. If one of the pumps went down, the right tools were always in his tool bag when he went to make his repairs. On stormy days, he'd usually find himself working on one of the pumps to deal with the excess volume from the seas above. Alternatively, on clear days, he'd hear the breach alarm go off and find some mortar mix and tools ready to make the patch. The dam would have already diverted the flow and he'd get to work roping himself down the massive face of the dam to keep it safe for yet another day.
On quieter days, he'd have time to think about this bizarre situation. He also found the time to explore the dam, which was clearly a magical place. The library was difficult to find but filled with more books than anyone could ever read in a lifetime, though the boy had spent many lifetimes exploring those pages as well.