Mae had got off the bike, and stepped in front of the headlamp. She was looking at the LCD readout on the counter. She said, "Hmmm."
Bobby said hopefully, "So, what do you say, Mae? Time to go back?"
"No," Mae said. "It's not time to go back. Take a look at this." Bobby leaned over, and we both looked at the LCD readout. It showed a graph of radiation intensity, stepping progressively downward, and finally dropping quickly. Bobby frowned. "And this is?"
"Time course of tonight's readings," she said. "The machine's showing us that ever since we started, the intensity of the radiation has declined arithmetically-it's a straight-line decrease, a staircase, see there? And it's stayed arithmetic until the last minute or so, when the decrease suddenly became exponential. It just fell to zero."
"So?" Bobby looked puzzled. "That means what? I don't get it."
"I do." She turned to me, climbed back on the bike. "I think I know what happened. Go forward-slowly."
I let out the clutch, and rumbled forward. My bouncing headlight showed a slight rise in the desert, scrubby cactus ahead ...
"No. Slower, Jack."
I slowed. Now we were practically going at a walk. I yawned. There was no point in questioning her; she was intense, focused. I was just tired and defeated. We continued up the desert rise until it flattened, and then the bike began to tilt downward-
"Stop."
I stopped.
Directly ahead, the desert floor abruptly ended. I saw blackness beyond.
"Is that a cliff?"
"No. Just a high ridge."
I edged the bike forward. The land definitely fell away. Soon we were at the edge and I could get my bearings. We were at the crest of a ridge fifteen feet high, which formed one side of a very wide streambed. Directly beneath me I saw smooth river rocks, with occasional boulders and clumps of scraggly brush that stretched about fifty yards away, to the far side of the riverbed. Beyond the distant bank, the desert was flat again. "I understand now," I said. "The swarm jumped."
"Yes," she said, "it became airborne. And we lost the trail."
"But then it must have landed somewhere down there," Bobby said, pointing to the streambed.
"Maybe," I said. "And maybe not."
I was thinking it would take us many minutes to find a safe route down. Then we would spend a long time searching among the bushes and rocks of the streambed, before picking up the trail again. It might take hours. We might not find it at all. From our position up here on top of the ridge, we saw the daunting expanse of desert stretching out before us. I said, "The swarm could have touched down in the streambed. Or it could have come down just beyond the bed. Or it could have gone quarter mile beyond." Mae was not discouraged. "Bobby, you stay here," she said. "You'll mark the position where it jumped. Jack and I will find a path down, go out into that plain, and run in a straight line east-west until we pick up the trail again. Sooner or later, we'll find it."
"Okay," Bobby said. "Got you."
"Okay," I said. We might as well do it. We had nothing to lose. But I had very little confidence we would succeed.
Bobby leaned forward over his ATV. "What's that?"
"What?"
"An animal. I saw glowing eyes."
"Where?"
"In that brush over there." He pointed to the center of the streambed. I frowned. We both had our headlights trained down the ridge. We were lighting a fairly large arc of desert. I didn't see any animals.
"There!" Mae said.
"I don't see anything."
She pointed. "It just went behind that juniper bush. See the bush that looks like a pyramid? That has the dead branches on one side?"
"I see it," I said. "But ..." I didn't see an animal.
"It's moving left to right. Wait a minute and it'll come out again." We waited, and then I saw a pair of bright green, glowing spots. Close to the ground, moving right. I saw a flash of pale white. And almost immediately I knew that something was wrong. So did Bobby. He twisted his handlebars, moving his headlamp to point directly to the spot. He reached for binoculars.
"That's not an animal ..." he said.
Moving among the low bushes, we saw more white-flesh white. But we saw only glimpses. And then I saw a flat white surface that I realized with a shock was a human hand, dragging along the ground. A hand with outstretched fingers.
"Jesus," Bobby said, staring through the binoculars.
"What? What is it?"
"It's a body being dragged," he said. And then, in a funny voice, he said, "It's Rosie."
DAY 6
10:58 P.M.
Gunning the bike, I took off with Mae, running along the edge of the ridge until it sloped down toward the streambed floor. Bobby stayed where he was, watching Rosie's body. In a few minutes I had crossed the streambed to the other bank, and was moving back toward his light on the hill.
Mae said, "Let's slow down, Jack."
So I slowed down, leaning forward over my handlebars, trying to see the ground far ahead. Suddenly the radiation counter began to chatter again.
"Good sign," I said.
We moved ahead. Now we were directly across from Bobby on the ridge above. His headlamp cast a faint light on the ground all around us, sort of like moonlight. I waved for him to come down. He turned his vehicle and headed west. Without his light, the ground was suddenly darker, more mysterious.
And then we saw Rosie Castro.
Rosie lay on her back, her head tilted so she appeared to be looking backward, directly at me, her eyes wide, her arm outstretched toward me, her pale hand open. There was an expression of pleading-or terror-on her face. Rigor mortis had set in, and her body jerked stiffly as it moved over low shrubs and desert cactus.