g with food enough for only one week because he couldn't buy
more, and he had stayed four, five, six weeks.

To do that he had had to experiment. He'd eaten all sorts of things.
Sometimes he had been ill but he had acquired immunity to certain
poisonous plants that contained food values.

The oxygen problem for a diving-suit for forty days would have stopped
most men but Grant had solved that too. If he had not, he never could
have gone to the Red Lava Range after the fabulous gizzard-stones of
Venus's prehistoric echindul.

For oxygen, he had discovered a plant that grew in the bottom of the
swamp. You could cut its stalk into sections and put them in a
container and they would exude oxygen for several hours. But he had to
carry at least one extra stalk all the time, and he had to keep his
eyes sharp for more. Sometimes it had been close.

Grant looked at the Red Lava Range and felt the precious leather bag
inside his shirt and smiled. Yes, he'd done it. He'd found one of the
fabulous nests of the echindul--and it had been loaded with stones,
just as ancient Venusian legend insisted.

The extinct echindul had been a sort of flying lizard that had nested
in the mysterious, almost inaccessible Red Lava Range. Every echindul
had had two gizzard-stones, and each matched pair of stones had an
unusual property.

Grant reached in his watch-pocket and brought out the one he had kept
out of the bag. He held it up and watched the sunlight, filtering
through Venus's thick clouds, and the firelight, reflected from Red
Lava Range two hundred miles away, play on the chatoyant interior of
the stone as if they were chasing each other.

Those stones would be worth forty thousand Earth dollars a pair if he
could get them to a reputable dealer in Aphrodite, Venus's largest
city. Therein lay Grant Russell's next problem, and in spite of the
satisfaction he felt at emerging from the Great Swamp, he knew that
getting safely to Aphrodite might be an even more serious problem.

Aphrodite's only approach over the Lead Vapor Mountains from the
southern hemisphere was through The Pass, a legalized city of vice. On
one side The Pass was flanked by the Bubbling Zinc Pits and on the
other side it was skirted by the Fluoride River, and man had not yet
devised any way to navigate either of these. It was doubtful, even,
that any species native to Venus could cross those two areas, but on
this authorities did not agree for in the year 2542 Ven