His friends laughed with him—ruefully—as they walked together across the campus.

Some minutes later Les Payten nodded to them, and, with a half smile, said, "So long for now. Don't lose any sleep—not over worries, anyhow."

He sauntered off. In matters of love, Les was a good loser.

Barbara Day had taken a little apartment on a tree-lined street. It was nice to walk there in the twilight. Not far from the apartment a half-acre of ground had been allowed to grow wild with trees and bushes, for contrast to the surrounding sleek neatness.

There, in the thick shadows, Ed Dukas saw sinuous movement. He had a fleeting glimpse of something long and winding, and perhaps half as thick as his body. Then he saw it again—saw its weird glow, saw the interlocking hexagonal plates that covered it everywhere. But it did not suggest a gigantic snake at all. For one thing, its mode of locomotion was different—a rippling movement of thousands of little prongs on its undersides seemed to be involved in its principle. It hurried quietly now for cover. Rhododendron bushes parted. It disappeared behind a great oak.

Barbara and Ed rushed forward. The grass bore no marks. Prudently, they did not venture into the dark undergrowth.

Ed's skin prickled all over and felt too small for him. "This is it," he said in a flat tone.

"What, Ed?"

"Life plotted on the engineer's drawing board. Vitaplasm. The days when nature designed all animals are over, I'm afraid."

"What would it be for, Ed?"