"I'm going to step up the beam," he said.

"But why? Why, Hilili? For the love you bear me—"

"I bear you no love."

"But you are my biogenetic twin, Hilili. We have been closer than ordinary brothers from birth."

"It does not matter. It does not concern me. Family relationships militate against survival when reason falters in a single member of a family group."

Tall-Thin's voice hardened. "We came to this planet for one purpose—to colonize it for the good of all. We numbered thousands and now we are reduced to a pitiful remnant—just ourselves. Thanks to the stupidity of a few."

"I was never one of the stupid ones!" Rujit protested. "I advised our immediate return. The unknown and hideous diseases which decimated us like migs, the atmospheric gases which rotted our ships so insidiously that we were not aware of the damage until they exploded in flight—remember, I kept insisting that we could not survive such hazards for long!"

"Your sound judgment in that respect was more than offset by your wilful insistence we explore the entire planet," Tall-Thin countered. "Our ships were so numerous that they were observed in flight and we might have been destroyed completely when death and disaster struck.

"As might have been expected the very shape of our ships made them conspicuous. Fiery disks they must have seemed to the Earth dwellers, so terrifying that they would have eventually found a way to fathom the mystery, and strike back. A perishing remnant of an advanced race has never yet succeeded in killing two billion primitives armed with Class C-type weapons."

"But how could I have known it then?"