The afternoon was cool and overcast. Grendel was anxious to pick up the pace but responded nicely when Gabe called for a walk. His first goal was to determine how far out on the trail they would be after twenty-five minutes. At that point, with luck, the Secret Service horses would be in no shape to match the speed with which he and Drew would take off. After their break from the agents, on the first acceptable trail to the left, the two of them would cut toward the paved road, which was smudged on the map but might have been Route 491.

Twenty-five minutes.

Gabe had subtracted five minutes from the thirty Ellen Williams had estimated in order to make up for the time it would take them to get back to the stables from where they would have mounted up at the rear entrance to Camp David.

Twenty-five minutes.

Gabe grinned at the notion of treating this operation as if this were some sort of science. The size of the horses minus twice the weight of the agents plus the rate of absorption of the Williams potion squared minus the angle of the sun equaled . . . twenty-five minutes. No problem.

At the spot on the trail, twenty-five minutes out, Gabe stopped Grendel, sharpened his hunting knife on a whetstone from his backpack, and marked several trees at horseman's eye level. They then proceeded at a careful walk, scanning along the left tree line for an opening. With luck, the next time he traveled over this portion of the trail, he and Drew Stoddard would be moving at a full gallop. He felt his mouth go dry at the prospect.

Is there any other way? he asked himself for the thousandth time. Is there any other way?

Now there were just three more pieces—a trail going off to the left toward the highway, a place to leave the horses where they would eventually be found, and finally a concealed spot just off Route 491 to leave the Impala. Gabe's best guess was that the car would have to remain undiscovered by the park rangers for at least two hours. If they found it and had it watched or towed, some trucker would have a hell of a tale to tell about the two guys he picked up hitchhiking.

The first piece, a trail to the left, was a narrow track that had some dried hoofprints but didn't look as if it were used much. It was just a few minutes from where Gabe hoped he and Stoddard would be leaving their posse—closer than he would have liked, but far enough to work, and perfect in every other respect. The tree marks here were critical in that he would have to see them at a gallop. He made a few cuts, then dismounted and built a subtle cairn of stones on the right side of the main trail, ten yards before the path.