"Hard time getting you into a suit when the ship's air went," remarked the navigator, his voice loud in Akars' earphones. "Of course I knew what was coming and had only to close my face plate, just as you told me. But I wanted to save you particularly. They need good, tough murderers like you at the mines. Some last as long as five years, I hear." Akars tried to sit up, discovered that he was bound--and that Jordan had the paralysis gun now. "I found the Urulium," continued the navigator. "The _Cinnabar's_ widows and orphans will get their share, after all." "What happened?" asked Akars thickly. "That explosion--" "Only a feeble imitation of the _Cinnabar's_. Don't forget that her fuel exploded spontaneously--with a thousand times the force. In our case the fuel was inert, because our refrigeration didn't fail. It _burnt_, once ignited, but without an explosion--just as I expected. What I didn't tell you, Akars, was that the collision you had near the wrecked _Cinnabar_ knocked a hole in one fuel tank. I was lying almost against it--almost froze, too--and for hours I could hear fuel leaking out through the rip. Not much--just enough to catch fire when that spark hit us, and to carry back and ignite the whole tank." Akars groaned. "That spark--that damn spark!" Jordan was staring into space. He rose and looked long, then sat down again. "We're rescued, Akars. Naturally the salvage ships kept a lookout for the missing life ship and saw the flare-up here. They'll arrive soon." "That spark!" groaned Akars. "What the devil was it?" "That was what you weren't interested in, Akars. The 'plus' of H277 plus. Did you know that the earth and most planets are negatively charged--have a surplus of electrons? And that our ships are also negatively charged--in fact super-charged because of the driving fields we use? A planetoid or asteroid with a simple name or number is also negative and no precautions are necessary. But a 'plus' following the designation means it is positively charged, whether because of interacting gravitational fields, internal radio-activity, or induction between the body and an atmosphere or some other reason. When an accredited navigator has to land on a 'plus' body he orders a careful check of all fuel tanks, because he knows there will be a heavy electrical discharge between it and the ship just before landing. But you didn't know that--