Which, as we all know by now, is exactly when the bad things happen. This time, it was the radio squawking. I sat up straight and grabbed for the walkie-talkie.

“We’re coming back fast,” Vance said. There was a lot of static and he was barely whispering, but my heart raced as I made out his words. “Get everything you can into the backpacks. We’re going to have to bug out.”

“What did you find?” I asked, whispering myself. Behind me Finster crouched down to try to hear better.

“About fifty of them, all coming up the same canyon. They’re spread out pretty loose, and I think I haven’t seen them all. There’s probably more. Probably a lot more. This is Tucson. Go, now. Get things ready-we won’t have time to pack when I get back.”

“Understood,” I said, and signed off. I turned to face Finster. His face was as white as-well, as white as a dead guy’s. “Let’s move,” I told him.

We cracked open one of the motel rooms we used as cold storage and found the back packs waiting for us on an unmade bed. Ten of them, still half-full of stuff we never bothered to unpack. Bottles of purified water, bags of beef jerky and boxes of hard crackers. Canned food is heavy and if you’re carrying your supply on your back it slows you down. Into each pack we put survival gear, camp stoves, thermal blankets, first aid kits. Knives, lots of knives and other basic weapons. As much water as we could shove into the packs. If we were going to walk across the desert until we found another safe place we would need a gallon per day per person. There was no way we could carry enough, but the supply we had would just have to do.

Finster and I didn’t talk while we worked. Candy was slung on my back, fast asleep. She learned how to do that very early on. When Mommy’s busy, you just go to sleep-that’s a survival strategy. Good girl.

I didn’t feel bad about having to abandon the motel. It had been a good place, a shelter in a dangerous world, and I had no idea where we would find anything like it again. But the rules of this world are very clear: When you have to move on, you go and you don’t look back.

The search party had taken all our guns, which wasn’t saying much-they had two revolvers and a.22 pistol between them, and enough ammo to reload once. I had my bow and my quiver and Finster had a slingshot, a high-tech geek toy that could put a ball bearing through a dead guy’s skull at twenty yards. We geared ourselves up and hauled the packs out to the motel’s courtyard so the search party could just grab and go.

It was only when all that was done that I realized neither of us had been watching Simon. Nobody would expect the boy genius to help us get ready, so I guess we just ignored him until it was time to get him prepared for the move. Vance and Joe, the two strongest men in our group, had a kind of stretcher they had built so they could carry Simon around. It even had a little canopy to keep the sun off of him. Simon hated the thing, though, and we never brought it out until it was absolutely necessary. Just seeing it would be enough to trigger one of Simon’s screaming fits.

“He’s probably in reception playing with the cable box, wondering why he can’t tune in The Brady Bunch or something,” Finster said, when I asked where Simon was.

“You check there. I’ll look in his room,” I told him.

But he wasn’t in his room. Finster shouted to say he wasn’t in the office, either. I jogged back and forth across the parking lot, calling him, but got no response. He didn’t seem to be anywhere inside the fence.

Then I spotted him, and I nearly yelped in horror.

He was outside the fence.

Lord knows how he made it all that way, crawling around on his arms. He had the gate open and had crossed both lanes of the highway beyond. There was a stoplight out there that hadn’t worked since Before, with a big electrical junction box at the base of its pole. Simon had the box open and was pulling wires out, making neat piles around him sorted by color. I called his name but he didn’t even look up.

“Damn it,” I said, exasperated. This wasn’t the first time Simon had put us in danger, and I doubted it would be the last. I ran over to him, my heart pounding the second I was outside the fence, even though there was no sign of the dead in either direction. I tried to grab his arm and lift him up but Simon just went limp and his arm slithered through my hands. “Simon, come on, we have to go.”

“Busy. Busy building,” Simon said. “Vance says I can build. Vance says you have to leave me alone while I’m building.”

“Sure,” I tried, “but right now we need you to build something inside the fence.”

“I’ll do that later,” Simon said.

There was nothing for it. I just didn’t have the upper body strength to pick him up and carry him, not when he was going to fight me. I needed to get Finster to help. So I hurried back toward the gate, shouting for Finster to come help.

I don’t know if he heard me or not. He was pretty busy just then.

Tucson had come for us.

Hundreds of them. Maybe a thousand.

I hadn’t seen anything like it since the last days of Vegas.

Their clothes hung on them in tatters, and their flesh had shriveled on their bones. They must have run out of food in Tucson a while back and desperate hunger had driven them this far. Their eyes were cloudy with sun damage and their skin was covered in sores. Many of them were missing limbs, or at least fingers, but they all had their legs intact. When I saw them I understood what had happened. The fifty Vance had found in the canyons were the slow ones, the ones that didn’t keep up.

This was the crowd that could still move at a good clip. The ones that were still mostly healthy, who had gotten ahead of the rest.

You always expect them to be an unruly mob, shoving at each other and snarling at the ones who would rob them of their food. It wasn’t like that, though. They were barely aware of each other, but all of them wanted the same thing. They knew Finster and I were inside that fence. They moved in concert, pushing forward all at once. Never making the slightest sound. It was easy for the dead to take us by surprise, because they were as silent as the grave.

They hit the fence like a human tsunami. That side of the fence had been the strongest part-we had reinforced an existing fence there that had been made to keep out coyotes. The dead had no trouble with it at all. It came jangling down and they climbed over what was left.

Finster was working overtime with his slingshot, firing his giant-sized BBs one after the other, grabbing them out of a sack on his belt. He was a crack shot with that thing and he didn’t hesitate, but he didn’t waste shots either, making sure every round he fired was a clean head shot that took down his target.

I could have run up and joined him, and fired every single one of my arrows into that crowd in the time we had. Even healthy dead people move slow. I could see right away it was pointless, though. Neither of us had anything like enough ammunition. “Finster,” I shouted, “stop-you can’t get them all!”

“You have a better idea?” he asked me. His eyes looked crazed and I thought he might be hyperventilating.

“Yes! Come on, this way.” I grabbed at his arm and he followed.

“Come on. The reception office has the thickest walls, and we can get a couple of doors between us and them,” I told him, dashing around the side of the pool’s pump house. The dead were hot on our heels but we had no problem outrunning them. I rushed out onto the pool deck with my bow in my hand, an arrow already half-nocked. Good thing, too, because a dead woman in a pantsuit was already there waiting for me. She came stumbling toward me with her arms out, like she wanted to give me a big hug. I put my arrow right through her eye and jumped over her as she collapsed.