The Observer

He is the best graduate of an academy that produces “progressors”—strong, smart guys who bring the inhabitants of alien planets under Earth’s knee.

However, his friends from the same cohort played a cruel prank on him: they swapped the “assignments” and accidentally sent the hero straight into the mouth of a volcano—onto a planet where semi-wild inhabitants don’t coexist very peacefully with technogenic masterpieces of a great space civilization, long gone into the abysses of the universe.