Without the ability to hover or levitate, climbing higher means putting forth more wing power or using updrafts. Far below his increasingly pale tiny-seeming shadow flickers and glides across the sand.

"I was born somewhere where if anyone disappeared it was because someone made them disappear, or they decided to disappear themselves. Then my best friend and I ended up somewhere with different rules, where the whole population of the world just vanished for no reason any of us could see," he tells her distantly. "I hate that kind of thing."