She looked at it and scowled—very prettily, but still a scowl. "What is this? It's a beautiful piece of stone."
"I picked it up myself," Johnny said. "Near Reggan. It's a chunk of petrified wood, Miss Desage. From a tree that must have originally had a diameter of some ten feet. Not quite a redwood, of course, but big."
"Yes," she said, turning it over in her hand. "I can see this part, which must have once been bark. But why do you show it to me?"
"The Sahara was once a semi-tropical, moist area, highly wooded. It can become so again."
She put the piece of fossil back on his desk. "How long ago?" she said bluntly.
"A very long time ago, admittedly. During the last Ice Age and immediately afterwards. But, given man's direction, it can be done again. And it must be."
She raised pencilled eyebrows at him. "Must be?"
Johnny McCord shifted in his chair. "You must be aware of the world's population explosion, Miss Desage. The human race can't allow three and a half million square miles of land to be valueless." He grunted in deprecation. "And at the rate it was going, it would have been four million before long."
She didn't understand.