The sow led her family off back into the brush, and a little farther on Rolf turned his bike from the concrete highway onto the asphalt road that led down in the direction of the Playalinda Beach part of the Refuge. Then, a short distance down the asphalt, he cut off the road entirely and bumped along on one of the old foot trails that wound through the Preserve.

Officially, no one was supposed to be here, right now. That was why he had not planned to come today. Playalinda Beach was officially closed when there was a rocket on the pad at LC-39, as the Mars rocket stood right now.

But who cared? All that the Beach’s being closed meant was that nobody else would be around. And who wants anybody else around? Rolf asked himself. It’s good to be alone. Nobody here except me and Shep.

Shep?

Rolf suddenly realized that Shep was no longer trotting beside his bike. By itself that wasn’t so odd, since the trail was too narrow in spots to let the bike and the dog go side by side. But in that case, Shep should be right behind him. Rolf glanced back, squinting against the glaring sunshine.

Shep was behind him, all right. But a long way behind. The sheepdog was sitting at the last bend of the trail they had passed, some fifty yards behind Rolf, gazing at him disapprovingly. Rolf braked the bike and stopped. He put his feet down on the sandy ground and half turned around.

“Come on!” yelled. “Shep! Come on!”

Shep didn’t move. But he barked—which complicated matters.

Shep wasn’t like other dogs, in a number of ways. One of these was the way he barked. He had a gruff voice, to begin with, but there was more to it than that. When most dogs bark they seem to be saying, “Hey, glad to see you!” or “Look out! Warning! Stand back!”