My Radio Shack homing device guided me through the Mesozoic heat back toward the Sternberger, an arrowhead on the unit’s LCD showing the direction from which it was receiving radio beeps. It wasn’t taking me along the same route I’d used going out, meaning, I guess, that I hadn’t ambled in a straight line. No matter. I didn’t mind cutting through the forest, since the shade shielded me from the inferno of the late-afternoon sun.

Klicks and I both carried portable radios, of course, but what I had to discuss with him required a face-to-face meeting. Even then, it would be hard to convince him of the incredible spectacle I’d just witnessed.

And yet, exactly what had I seen? A fight involving animals? They still allow bullfights in Spain, and just the week before we’d left, I’d read about a dog-fighting club in Oakville being charged by the local police. If the Hets had stumbled onto humans involved in those cruel sports, what would they have made of us?

But no. What I’d observed was clearly something more, something on a grander, sicker scale.

War games.

But who could they be fighting? What kind of squat, low foe had those mechanical-tank doorways originally been designed to accommodate? That the beetle-like vehicles weren’t of Martian manufacture I felt sure. Captured war machines, then — spoils of some previous skirmish, now used to train living armored vehicles. The triceratopses were clearly expendable.

Het slimeballs rode within them, jerking the dinosaurs’ strings like dragon marionettes.

Was there another civilization on Earth at this time? Had the Hets come here to invade this planet? My sympathies immediately went to the beleaguered Earth beings, a knee-jerk reaction. But it all seemed so incredible, and so unlikely. In China, in Russia, in Australia, in Italy, in England, in the United States, and in Canada paleontologists had examined rocks from the end of the Mesozoic, painstakingly sifting for even the smallest bone chip. It was inconceivable that the remnants of a large-scale technological civilization could pass unnoticed through such scrutiny. But, then, who were the Hets fighting?

I was having trouble thinking clearly — my head pounded with an ache brought on by the heat. The backs of my hands were tingling and I realized too late that they, the only exposed skin on my body, had been sunburned. The presence of all these deciduous trees seemed clear evidence that seasons were well established by this point in Earth’s history, but we must have arrived in high summer. To make matters worse, somehow an insect had gotten under my cheesecloth face mask and bitten my neck, the puncture swelling and itching.

As I made my way back, I came across a couple of wild hadrosaurs, spatulate bills nipping in and out of clusters of pine needles, the horny sheaths impervious to the sharp jabs. Their up-and-down chewing, so unlike a cow’s, made sounds similar to wood rasps as the batteries of thousands of flat molars ground the foliage and small cones. This was the closest I’d come to any large living dinosaurs outside of the protection of the Jeep. I could hear their stomachs rumbling and was made woozy by the pungent methane wind they gave off.

I also ran into my first mammal, a chocolate-colored furball with long limbs, a naked rat-like tail, and an inquisitive chipmunk face, complete with little triangular ears on top. Mammalian paleontology wasn’t my field, but I fancied that this little beast might even have been Purgatorius, the first primate, known from a lot of Paleocene material from nearby Montana and from one admittedly contested tooth from the very end of the Cretaceous.

We regarded each other for thirty seconds or so, the mammal’s quick black eyes locked with mine. For me, it was a special moment, meeting my great-to-the-nth grandfather, and I kidded myself that the little proto-monkey sensed our kinship, too, for he didn’t scamper away until one of the hadrosaurs let out a multi-toned bleat. I watched him scurry off into the undergrowth, feeling both sad and proud that soon he would no longer have to peep around the legs of the mighty colossuses that now strode the land. The meek shall inherit the Earth…

The little arrow on my homing device told me that I should go straight ahead, but the forest looked dense that way, with thick vines and foliage like cooked spinach draped from the branches. If I veered to the east, perhaps that would -

Claws dug into my right shoulder.

My heart skipped several beats. I jumped forward and twisted around, fumbling for the rifle in my backpack. A troodon stood there, its drawn-out head tilted to one side, great unblinking eyes regarding me. Was the beast Het-ridden? Or was it wild? I rested the butt of the rifle against my shoulder and the two of us continued to stare at each other. This troodon was smaller than the ones Klicks and I had encountered earlier, and its face was freckled with brown spots. Probably a male.

"No."

The word, as before, sounded raw, torn from the animal’s throat. That the reptile was a vehicle for a Het made me no less nervous. In fact, I thought I’d better take some precautions. "Back off," I said. "I want you to stay at least five meters away from me."

"Why?"

"So you won’t try to enter me."

"Why?"

"I don’t trust you."

"What is trust?" said the thing.

"Back off! Now!" I gestured with the rifle.

The troodon hesitated for a moment, then took a couple of steps back.

"Farther," I said.

It took two more long steps.

I set the rifle on the ground in such a way that I could scoop it up in an instant. I then swung my backpack off my shoulders. Inside I had a bunch of things, including two cans of Diet Coke and our only can amongst all our provisions of diet A W root beer. I grabbed the root beer with my left hand and fumbled for my walkie-talkie with my right. I thumbed the unit on. "Klicks?"

Static for several seconds. Then: "Hey, Brandy — good to hear from you. Listen, I’m finding a dusting of iridium in a recent sedimentation layer, all right — as you’d expect given the impact crater we saw in Mexico — and there’s some shocked quartz, too. But neither are present in the quantities I’d have anticipated based on terminal-Cretaceous samples collected in our time, and—"

"Not now," I said.

"What?"

"I’ve been approached by another troodon occupied by a Het."

"Where are you?"

"About ten kilometers west of the Sternberger, I think."

"I’m at least twenty-five kilometers east," said Klicks. Probably a couple of hours’ drive for him, given the rough terrain.

"Klicks, I’m holding in my hand a can of A W diet root beer."

The troodon tilted its head at me oddly.

"Good for you," said Klicks.

"Shut up and listen," I snapped. "I’m holding the only can we’ve got of A W diet root beer. I’ve got my finger on the pull-tab. If the troodon gets too close to me, or if I’m attacked in any way, or any attempt is made to enter me, I’ll pull the tab."

"I don’t—"

"When you next see me, make me show you the can. Make sure it’s unopened."

"Brandy, you’re paranoid."

The troodon’s head bobbed. "Un-nec-esss-ary," it hissed.

"Klicks, I want you to get some object that you can use the same way," I said into the walkie-talkie. "I want you to have a signal for me."

"Brandy—"

"Do it!"

Static again. Then: "I’ve got a pen here. I could click it open if I’m entered."

"No. It’s got to be something that’s not undoable. Something you can do fast. And something that we only have one of."