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