in an essential enzyme system. Knowing this, Tiger quickly found a drug
which could be substituted for the damaged enzyme, and the problem was
solved. They left the planet, assuring the planetary government that
laboratories on Hospital Earth would begin working at once to find a way
actually to rebuild the damaged genes in the embryonic cells, and thus
put a permanent end to the disease.

These were routine calls, the kind of ordinary general medical work that
the patrol ships were expected to handle. But the visits to the various
planets were welcome breaks in the pattern of patrol ship life. The
_Lancet_ was fully equipped, but her crew's quarters and living space
were cramped. Under the best conditions, the crewmen on patrol ships got
on each other's nerves; on the _Lancet_ there was an additional focus of
tension that grew worse with every passing hour.

From the first Jack Alvarez had made no pretense of pleasure at Dal's
company, but now it seemed that he deliberately sought opportunities to
annoy him. The thin Blue Doctor's face set into an angry mold whenever
Dal was around. He would get up and leave when Dal entered the control
room, and complained loudly and bitterly at minor flaws in Dal's
shipboard work. Nothing Dal did seemed to please him.

But Tiger had a worse time controlling himself at the Blue Doctor's digs
and slights than Dal did. "It's like living in an armed camp," he
complained one night when Jack had stalked angrily out of the bunk
room. "Can't even open your mouth without having him jump down your
throat."

"I know," Dal said.