“There are four of us,” answered Warley, “we are Englishmen, who have been wrecked on the western coast, and are now trying to make our way to Cape Town.”

“Indeed,” returned the stranger, “but you are aware, I presume, that this is not the nearest way from the west coast to the town you name. You have come a long distance out of your way and chosen a very undesirable route.”

“No doubt,” said Ernest, “but we could not help ourselves. We fell in with a Hottentot tribe, and have had a narrow escape from their hands. But we are in a great strait now. One of our party has incautiously drunk a quantity of water at a fountain near here, which we have since discovered to be poisoned; and none of us—”

“What the spring in the kloof, about two miles back, I suppose,” interrupted the stranger. “I passed it two or three hours ago. I noticed that it had been poisoned—poisoned by euphorbia juice. Your friend cannot have had much experience of the Kalahari, or he would have detected it at once. You may always know water poisoned in that manner by its clay-like appearance. How much did he drink?”

“A long draught, I am afraid,” said Ernest. “I was not present, but he said so.”

“How long ago?”

“I should think two hours.”

“There is no time to be lost, if his life is to be saved,” observed the unknown. “Happily, the antidote is easily found in these parts. When, indeed, are God’s mercies ever wanting in the hour of need!”

He spoke the last sentence to himself, rather than to his companion. Drawing forth his flint and steel, he struck a light, by which he kindled a small lantern, which was one of the articles appended to his belt. By the help of these, he began searching among the herbage which grew thickly on either side of the path. Presently he lighted on the plant of which he was in quest. It was shaped something like an egg, which it also nearly resembled in size. He pulled up two or three specimens of this, and shook the dirt from the roots. Then he again addressed Warley.

“Where is your friend?” he said. “At the kloof, where he drank the water, I suppose? You had better take me to him as quickly as possible.”