"Neutrons—don't you see?"
"Frankly, I don't. I'm no scientist—merely a technician. Neutrons aren't used in any process I've run across."
"Well, remember they're uncharged, tiny things. Small as protons, but without electric field. The result is they pass right through an ordinary atom without being stopped unless they make a direct hit. Tungsten, while it has a beautifully high melting point, is mostly open space, and a neutron just sails right through it, or any heavy atom. Light atoms stop neutrons better—there's less open space in 'em. Hydrogen is best. Well—a man is made up mostly of light elements, and a man stops those neutrons—it isn't surprising it killed those other fellows invisibly, and without a sound."
"You mean they bathed that ship in neutrons?"
"Shot it full of 'em. Just like our proton guns, only sending neutrons."
"Well, why weren't we killed too?"
"'Water stops neutrons,' I said. Figure it out."
"The rocket-water tanks—all around us! Great masses of water—" gasped Cole. "That saved us?"
"Right. I wonder if they've spotted us."