Pitt nodded. "By riding up the Paradise's entrance shaft to this level, they saved climbing the vertical shafts we were forced to struggle through."

"It's almost as if they were looking for us," Marquez murmured.

Pitt didn't voice his thoughts to the others, but he was certain that once the bikers had ridden to the upper levels to escape the flooding, they had then followed in the footsteps of the four of them.

"It's all so crazy," said Pat, staring dazedly at the dead bikers. "What did he mean, we were 'involved with matters far beyond our comprehension'?"

Pitt shrugged. "That's for others to decide. The question in my mind is who sent them? Who do they represent? Beyond that, I'm only a marine engineer who is damp and cold and wants to find a thick Colorado prime rib medium rare and a gla.s.s of tequila."

"For a marine engineer," said Ambrose, grinning, "you're pretty handy with a gun."

"It doesn't take virtuosity to shoot a man from behind," Pitt came back cynically.

"What do we do with him?" inquired Marquez, pointing at the biker Pitt had clubbed senseless.

"We've no rope to tie him up, so we'll take his boots. He won't get far in bare feet through the mine tunnels."

"You want to leave him?"

"No sense in hauling an inert body around. Chances are, by the time we notify the sheriff and he sends his deputies down here, the killer will still be unconscious." Then Pitt paused and asked, "Have any of you ridden motorcycles?"

"I rode a Harley for ten years," answered Marquez.

"And I have an old Honda CBX Super Sport that belonged to my dad," Pat volunteered.

"Do you ride it?"

"Rode it all through college. I still hit the roads with it on weekends."

Pitt looked at Pat with newfound respect. "So you're an old leather-crotch, hard-in-the-saddle woman."

"You got it," she said proudly.

Then he turned to Ambrose. "And you, Doc?"

"Never sat on a motorcycle in my life. Why do you ask?"

"Because we've got what look like three perfectly good Suzuki RM125 supercross bikes, and I see no reason why we can't borrow them and ride out of the mine."

Marquez's teeth showed in a wide smile. "I'm with you."

"I'll wait here until the sheriff shows up," said Ambrose. "The rest of you get going. I don't want to spend any more time with a live killer and two dead men than I have to."

"I don't like leaving you here alone with this killer, Doc. I'd prefer that you ride behind me until we're out of here."

Ambrose was firm. "Those bikes don't look like they were meant to haul pa.s.sengers. I'm d.a.m.ned if I'll ride on one. Besides, you'll be traveling over rail tracks, making it unstable as h.e.l.l."

"Have it your way," said Pitt, giving in to the obstinate anthropologist.

Pitt crouched and removed the P-10 automatics from the bodies. He was anything but a born killer, but he showed little remorse. Only a minute earlier, these men had been intent on murdering three innocent people whom they had never met-an act he could never have allowed to happen under any circ.u.mstances.

He handed one of the guns to Ambrose. "Stay at least twenty feet away from our friend, and stay alert if he so much as blinks." Pitt also gave Ambrose his dive light. "The batteries should last until the sheriff comes."

"I doubt if I could bring myself to shoot another human," Ambrose protested, but his voice came with a cold edge.

"Don't look upon these guys as human. They're cold-blooded executioners who could slit a woman's throat and eat ice cream afterward. I warn you, Doc, if he looks cross-eyed at you, brain him with a rock."

The Suzukis were still idling in neutral, and it took them less than a minute to figure out the shift, brake, and throttle controls. With a farewell wave to Ambrose, Pitt roared off first. There was no room for the machines to move between the outer rails and the walls of the tunnel, not without sc.r.a.ping the handgrips on the rough granite. Pitt kept his wheels in the center of the rail tracks, closely followed by Pat and Marquez. Bouncing over the rail ties with rigid suspensions rattled their teeth and made for uncomfortable riding. Pat felt as if her insides were being shaken around by a Laundromat dryer. Pitt found the trick was to find the proper speed that gave the least vibration. It worked out to twenty-five miles an hour, a speed that might have seemed slow and safe on a paved road but was quite dangerous inside a narrow mine tunnel.

The hard-rock acoustics made the exhaust blast echo in their ears. The beams from the headlights hopped up and down, striking the rails and overhead timbers like strobe lights. He narrowly missed an ore car that was sitting on the tracks and partially protruding from an intersecting tunnel. After riding up the gentle grade of a lift shaft, they reached the upper level to a mine that was labeled "The Citizen" on Pitt's directional computer. Pitt rolled to a stop where the tunnel met another at a fork and consulted the tiny monitor.

"Are we lost?" Pat queried above the rattle from the exhaust pipes.

"Another two hundred yards down the tunnel on the left and we should come to the end of the mine tunnel you said comes out under the New Sheridan Hotel."

"The entrance to the O'Reilly Claim was covered over a hundred years ago," said Marquez. "We'll never get out that way."

"Never hurts to look," said Pitt, shifting gears and easing the clutch on the Suzuki. He gave the bike a burst of speed and was forced to brake hard within two minutes, when he suddenly confronted a brick wall that solidly blocked the old mine entrance. He came to an abrupt stop, leaned the bike against a timber, and studied the bricks under the headlight.

"We'll have to find another way," said Marquez, as he pulled alongside, came to a stop, and set both feet on the ground to keep the bike upright. "We've come out at the bas.e.m.e.nt foundation wall of the hotel."

Pitt appeared not to have heard him. As if his mind was a thousand miles away, he slowly reached out and ran his hand over the old kiln-dried red bricks. He turned as Pat stopped her bike and turned off the ignition.

"Where do we go now?" she asked, her voice betraying near-total exhaustion.

Pitt spoke without turning. "There," he answered offhandedly, pointing in the general direction of the brick wall. "I suggest you both move your bikes to the side of the tunnel."

Pat and Marquez didn't get it. They still didn't get it after Pitt climbed on the Suzuki, revved up the engine, and spun gravel under the rear wheel as he rode back into the tunnel. After a short minute, he was heard accelerating down the tracks toward them, the Suzuki's headlight beam dancing madly off the timbers.

Marquez reckoned Pitt was doing nearly thirty miles an hour when he thrust out his legs and dug his heels onto the twin ore cart rails less than ten yards from the wall, released his grip on the hand controls, and stood up, allowing the Suzuki to speed on from under him. Slumped backward to compensate for his momentum, he actually remained upright for nearly twenty feet before his feet slipped off the rails and he folded into a ball before tumbling through the tunnel like a soccer ball.

The motorcycle stayed on its wheels, but was just starting to lie on its side when it crashed into the brick wall with a protesting screech of metal and a cloud of dust, before bursting through the old decaying bricks and vanishing into the void beyond.

Pat ran over to Pitt's body, which had skidded to a stop and was sprawled on the ground. She would have sworn he had killed himself, but he looked up at her, blood streaming from a gash on his chin, and grinned like a madman. "Let's see Evel Knievel try that one," he said.

Pat stared down at him in amazement. "I can't believe you didn't break every bone in your body."

"None broken," he muttered in pain, as he slowly rose to his feet. "But I think I bent a few."

"That was the craziest thing I ever saw," mumbled Marquez.

"Maybe, but it worked better than I expected." Pitt, clutching his right shoulder, nodded at the hole in the brick wall. He stood there, getting his breath and waiting for the pain from bruised ribs and a dislocated shoulder to ease, while Marquez began pulling away the bricks loosened by the bike's pa.s.sage to enlarge the entry.

The miner peered around the fractured wall and aimed his miner's lamp inside. After a few seconds, he looked back and said, "I think we're in deep trouble."

"Why?" asked Pat. "Can't we get out that way?"

"We can get out," said Marquez, "but it's going to cost us big time."