They were standing on a little clearing in a thick, low forest; there were trees and shrubs and a close, thorny, tangly undergrowth. In front of them stretched a bank of strange black mud, then came the browny-yellowy shining ribbon of a river. Then more dry, caked mud and more greeny-browny jungle. The only things that told that human people had been there were the clearing, a path that led to it, and an odd arrangement of cut reeds in the river. They looked at each other. “Well!” said Robert, “this _is_ a change of air!” It was. The air was hotter than they could have imagined, even in London in August. “I wish I knew where we were,” said Cyril. “Here’s a river, now—I wonder whether it’s the Amazon or the Tiber, or what.” “It’s the Nile,” said the Psammead, looking out of the fish-bag. “Then this is Egypt,” said Robert, who had once taken a geography prize. “I don’t see any crocodiles,” Cyril objected. His prize had been for natural history. The Psammead reached out a hairy arm from its basket and pointed to a heap of mud at the edge of the water. “What do you call that?” it said; and as it spoke the heap of mud slid into the river just as a slab of damp mixed mortar will slip from a bricklayer’s trowel. “Oh!” said everybody. There was a crashing among the reeds on the other side of the water. “And there’s a river-horse!” said the Psammead, as a great beast like an enormous slaty-blue slug showed itself against the black bank on the far side of the stream. “It’s a hippopotamus,” said Cyril; “it seems much more real somehow than the one at the Zoo, doesn’t it?” “I’m glad it’s being real on the other side of the river,” said Jane. And now there was a crackling of reeds and twigs behind them. This was horrible. Of course it might be another hippopotamus, or a crocodile, or a lion—or, in fact, almost anything. “Keep your hand on the charm, Jane,” said Robert hastily. “We ought to have a means of escape handy. I’m dead certain this is the sort of place where simply anything _might_ happen to us.” “I believe a hippopotamus is going to happen to us,” said Jane—“a very, very big one.” They had all turned to face the danger. “Don’t be silly little duffers,” said the Psammead in its friendly, informal way; “it’s not a river-horse. It’s a human.” It was. It was a girl—of about Anthea’s age. Her hair was short and fair, and though her skin was tanned by the sun, you could see that it would have been fair too if it had had a chance. She had every chance of being tanned, for she had no clothes to speak of, and the four English children, carefully dressed in frocks, hats, shoes, stockings, coats, collars, and all the rest of it, envied her more than any words of theirs or of mine could possibly say. There was no doubt that here was the right costume for that climate.