A man engineered to feel no pain travels the universe as an unwilling scout.
"Articulated motors were installed to move his limbs. Despite himself, a kind of zest grew. Two planets later he found industries and wrecked himself in a punch press. But on the next landing he tried to repeat it with a cliff and bounced on invisible force-lines. These precautions frustrated him for a time, until he managed by great cunning again to rip out an entire eye."