From his backpack he took a pair of riding gloves—something he would never wear if he weren't trying to keep himself from absorbing enough mixture through his palms to topple from his own saddle. While rummaging through the backpack, he eased the top off the Tupperware container, separated out three packets of soaked gauze—two pads in each—and replaced the top. At that instant, his radio crackled to life, actually startling him.

"Doc, this is Griswold. Are you there? Over."

"Griz, g'day, mate. I'm here at the rear gate. Got some mighty fine mounts for you. Over."

"We'll be there in five minutes, just as soon as the nurse and corpsman finish loading up the van. Over and out."

Gabe felt himself go cold.

"Joe, what kind of van is he talking about?"

"The medical van, of course. The president never goes out on the trail without three or four Secret Service agents and the medical van. Hey, wait a minute, aren't you the doctor?"

"The new doctor," Gabe corrected, his mind swirling. "I've never been out on the trail before."

So much for carefully contrived scientific formulas. How in the hell could Drew not have mentioned that there was going to be a van tagging along?

Gabe began rapidly flipping through what little he knew about disabling cars. The best he could come up with on the spot was dropping the sugar lumps he was carrying into the gas tank and hoping for the best. Ludicrous.

"Joe, what happens with the van if we go on a narrower trail?" he asked.

"The van waits where it can. A couple of years ago, one of the horses threw a guest and the man broke his leg. The agents had to carry him back down the trail to the van."

No help.

What a mess!

Gabe glanced at his watch. Even if he and Drew managed to disable the horses and take off, the van would be able to haul the agents back to camp in a matter of minutes. The two of them might not even be in the Impala before a massive pursuit began, with the Secret Service prominently represented in Marine One.

Why in the hell did he ever think he could pull this off?

"Doc, Griswold here. The van's all set. We're on our way. Over and out."

Damn!

"Joe," he said, handing over the two apples, "could you give these to Grendel and Mr. Please? I'm going to check the saddles one last time. I'm in no mood to play doctor out there."

Moving quickly, he crossed behind the horses, feigning a check of the blankets, stirrups, and cinches, while at the same time sliding the gauze as far up under the saddle blankets as possible. He was just easing the third pack into place when the president's entourage appeared and approached the guardhouse.

Gabe glanced at his watch and mentally started timing absorption of the drugs. Thirty minutes.