He looked down at the flag in his lap, then up at the dog, and his mouth moved like he was saying something I couldn't hear.

We moved through the waist-deep freezing water, using the reeds as camouflage. Every muscle in my body seized from the hypothermic chill of the river, but Rex swam silently, keeping his body between me and the sweeping halogen beams of the patrol boats. His discipline was inhuman; not a single splash, not a single heavy breath betrayed our position.

A spotlight swept within inches of my head, catching the floating debris from the mill explosion.

"Check that brush pile!" a voice echoed across the water through a tactical headset. "Thermal’s picking up residual heat signatures!"

"It's just runoff from the blast," a second voice replied from the boat's helm. "Command wants the dog confirmed dead. Bring up the drone."

The high-pitched buzz of a quadcopter drone rose above the hum of the boat engines. If they put an aerial infrared sensor directly above the water, the heat from our bodies against the cold river would light us up like flares on a radar screen.

Rex knew the sound. His ears flattened, and without hesitation, he clamped his jaws onto a heavy, floating log tangled in the river weeds, dragging it over our heads. We submerged ourselves until only our noses broke the surface beneath the rotting bark of the drift log.

The drone hovered directly overhead. The downdraft churned the surface of the river into white foam, spraying freezing mist into my eyes. My lungs burned; the cold was creeping into my bones, turning my fingers numb. I couldn't feel the rucksack. I couldn't feel my father’s shotgun.

All I felt was Rex’s side pressed against my chest under the water—radiating an incredible, stubborn furnace of heat. He was keeping my heart beating through sheer proximity.

Ten agonizing seconds passed. The drone banked left, accelerating toward the burning mill ruins.

"Area clear," the radio crackled. "Sweeping downstream."

The patrol boats powered up, their wakes rolling heavily over our hiding spot, churning mud and diesel fumes across the reeds. We waited until the red running lights disappeared around the river bend before pulling ourselves up onto the southern bank.

I collapsed onto the wet stones, shivering uncontrollably.

Rex stood over me, aggressively licking my face, using his body weight to force circulation back into my chest. He was shivering too, his thick double coat soaked and heavy with river silt, but he refused to lie down.

He nudged the canvas rucksack with his nose. The titanium drive was still inside, undamaged.

"We have to get to Richmond," I whispered through chattering teeth. "We have to reach the courthouse."

Rex suddenly turned his head south, sniffing the wind. His body went rigid once more. He didn't look at the road. He looked toward the deep, jagged spine of the Blue Ridge mountains.

He gave three short, clipped whines, then grabbed my jacket cuff again, tugging south.

He wasn't taking me to the highway. He was taking me to the one place my father had always told me never to go.