"Keep a close watch," said the radioman. "Abort if it drops below twenty-five percent."

"Roger that."

"Big Bertha does the scouring," Rush resumed. "Then, the grid square is examined for hits--holes or tunnels in the swamp bed. If there aren't any, the square is marked as explored and we move to the next square on the Grid. If tunnels are found, they're flagged as Search for the next team of divers."

"Might find a sinkhole," said Valentino. "Might find nothing. But we got to check each one. Sometimes the tunnels, they branch out. Then we have to map it--map it all."

Rush nodded at the monitor again. "And the results are recorded on that--and on the main cartographic display in the Operations Center--with archaeological precision."

"Found anything yet?"

Rush shook his head.

"And how much of the Grid have you explored so far?"

"Forty-five percent," Valentino replied. "By tonight, Madonna willing, fifty percent."

"That's fast work," Logan said. "I had a.s.sumed--"

He was interrupted by a loud voice over the radio. "This is Echo Bravo. There's a problem with my regulator."

"Check the purge valve," the man at the radio said.

"I did. Nothing."

Logan glanced quickly at Rush.

"It's probably nothing," the doctor said. "As you can imagine, diving in these conditions is tough on equipment. In any case, the respirators are designed to fail open--even if one malfunctions it will keep delivering air."

"Echo Bravo to base," came the voice. "I'm not getting air!"

Immediately, Valentino walked over to the radio and took the handset himself. "This is Valentino. Use your backup second stage."

"I am! I am! I'm getting nothing. I think the dust cap is blocked!" Even over the radio, the panic in the man's voice was evident.

"Romeo Foxtrot," Valentino said into the radio, "do you see Echo Bravo? His regulator's malfunctioning and his octopus is apparently detached. You need to share air. Do you see him? Over!"

"Romeo Foxtrot here," came the other amplified voice. "No sign of him. I think he's purging, heading topside--"

"Oh, Christ," said Rush. "Forsythe is panicking. Forgetting the rules." He turned to the nurse. "Get a crash cart and an emergency team here--right now. And bring the water seal."

"What's the problem?" Logan asked.

"If he remembers his basic training, nothing. But if he panics, holds his breath as he surfaces ..." Rush fell silent a moment. "For every thirty-three feet you descend, the air in your lungs loses half its volume to pressure. They were at thirty-five feet at last report. If he surfaces with all that air in him--"

"It will expand to twice its size," Logan said.

"And rupture his lungs." Grim faced, Rush hurried to the medical station, where the nurse was talking rapidly into a phone.

10.

They gathered around the dark, yawning circle of the Maw: tense, tight-lipped. At Valentino's clipped order, additional lights were snapped on overhead, throwing the shivering, quaking surface below into sharp relief. As Logan stared down at it, it seemed to him that the Sudd was a living thing, its brownish surface the skin of some vast beast, and that their perching on it like this was an act of monumental folly....

And then one of the cables leading down into the mire jerked spasmodically, and a strange gargling noise sounded over the radio.

Valentino ran back to the transmitting station. "Echo Bravo? Echo Bravo!"

"Romeo Foxtrot here," came the disembodied voice. "Still no sign of him. It's black as h.e.l.l down here, can't see a thing--"

With a clatter, two white-clad medics appeared at the entrance to Yellow, each pushing large carts full of medical equipment.

There was another jerk on the cable as the radio sounded again. "Romeo Foxtrot to base, I see him. I've got hold of him. Surfacing now."

Suddenly, the mottled surface of water and decayed vegetation began to churn and heave. A moment later, a black-gloved hand abruptly broke the surface, grasping a rung of one of the ladders. This was followed by a neoprene hood and mask. Despite the air of crisis, Logan was momentarily arrested by the strangeness of the image: the emerging diver seemed like an insect, struggling to break free from some primordial ooze.

Beside him, Dr. Rush had been waiting, tense and silent, like a coiled spring. Now he dashed forward and--with the help of one of the medical technicians--began to free the man from the Sudd's grip. The diver had his arm around a second neoprene-clad man, who was struggling weakly. The two were pulled up out of the Maw and onto the floor of the Staging Area. Both were covered head to foot with matter the consistency of oatmeal. The room suddenly reeked of decay and dead fish.

"Hose them down," Valentino ordered.

But even as a team rushed to blast the muck from the divers, Dr. Rush was shifting the injured man to a waiting stretcher. He plucked the mask and hood from his face, then--with a scalpel--slashed the neoprene suit open from neck to navel. The man moaned and thrashed on the stretcher, b.l.o.o.d.y foam flecking his lips.

Quickly, Rush placed a stethoscope on the man's bare chest.

"He panicked," the other diver said as he came over, wiping his face and hair with a towel. "A rookie mistake. But diving in that s.h.i.t, you forget--"

Rush raised a hand for silence. He moved the stethoscope around the chest, listening. His movements were jerky, almost violent. Then he straightened. "Extravasation of air," he said. "Resulting in pneumothorax."

"Doctor," said the nurse, "we can take him to Medical, where the--"

"There's no time!" Rush snapped as he pulled on a pair of latex gloves. The man on the stretcher twitched, clawing at his throat, gargling inarticulately.

Rush turned toward the medics. "A needle aspiration would be insufficient. Our only option is a thoracoscopy. Give me the chest tube, stat!"

Logan looked on with mingled surprise and apprehension. Up to this point, Ethan Rush had been the epitome of calm a.s.surance. But this--the sudden, almost frantic movements, the impatience and barked orders--was a Rush he had not seen before.

While one of the medics turned to his crash cart, Rush swabbed an area beneath the diver's left arm with iodine and a topical anesthetic, and then--with another swipe of the scalpel--made a two-inch incision between the ribs. "Hurry up with that chest tube!" he said over his shoulder.

The medic brought it over, unwrapping it from the sterile covering. Rush knelt before the struggling man and carefully threaded it into the incision he had made. He checked the placement, grunted, then rose.

"Chest drain," he rapped.

Another medic trotted over, pushing a floor stand that held a white-and-blue plastic device that, to Logan, looked like a blood-pressure monitor on steroids. It had several vertical gauges, and two clear plastic tubes led away from its upper housing.

"Suction-control stopc.o.c.k?" Rush barked.

"On."

"Fill water seal to two millimeters."

"Yes, Doctor."

As the medic added water to the device, Logan saw the reservoir chamber turn blue. Meanwhile, Rush attached one of the plastic tubes to the line inserted into the injured diver's chest. Logan glanced over at the diver: his struggles were weaker now, his movements erratic.

"Catheter in place," Rush said. "Initiating suction. Setting pressure at minus twenty cm H2O." He snapped a switch on the device, then began turning a stopc.o.c.k on the unit's housing. Instantly, the liquid in the suction control chamber began to bubble. Rush turned the stopc.o.c.k farther; the bubbling increased. The tube leading from the incision in the diver's side began to fill with mingled water and blood.

"If we can get the fluid out of the thoracic cavity quickly enough, the lungs might reinflate," Rush told the medical tech. "There's no time to operate."

The large room fell silent except for the hum of the machine and the bubbling of water draining from the tube.

Rush looked from the man on the stretcher to the water seal and back again in growing agitation. "He's becoming cyanotic," he said. "Increase vacuum pressure to negative fifty mmHg."

"But such a high level--"

Rush rounded on the tech. "d.a.m.n it, just do it." Then, walking briskly around the stretcher, Rush opened the now-motionless diver's mouth and began administering artificial respiration. Fifteen seconds pa.s.sed, then thirty. And then, quite suddenly, the diver's limbs jerked; he coughed up blood and water and then took a deep, ragged breath.

Slowly, Rush straightened. He looked at the diver, then at the water seal. "Dial it back to negative twenty," he murmured.

He glanced around at the a.s.sembled faces, then pulled off the gloves. "Keep an eye on the collection chamber," he told the nurse. "I'll go prep medical for a thorough evaluation." And without another word, he turned on his heel and strode out of the Staging Area.

As lunchtime approached, Logan found that his feet--he'd been wandering around the facility, trying to get his bearings--had brought him unbidden to what appeared to be the medical center. If there were really only a hundred and fifty people on the project, Medical seemed to him larger than necessary--until he recalled how far they were from any kind of help.

The center seemed quiet, almost somnolent. Logan walked down the central corridor, looking through the open doorways, at the empty beds and unused equipment. A woman at the nurse's station was making notations on a clipboard. He pa.s.sed a large open area labeled OBSERVATION. The injured diver was here, surrounded by various diagnostic machines.

Logan continued, stopping at the next room. This was apparently Rush's office; the doctor was inside, his back to the door, speaking into a digital voice recorder.

"A catheter was inserted into the thoracic cavity and tension pneumothorax alleviated before the condition could degrade to a mediastinal shift or air embolism," he recited, "either of which might have caused the case to terminate fatally, due to the fact that under the circ.u.mstances it would have been unfeasible to ..."

Realizing someone else was in the office, Rush snapped off the recorder and turned around. Logan was shocked by what he saw: the man's face was gray, his eyes puffy and red. It looked almost as if he had been crying.

The doctor gave a small smile. "Jeremy. Have a seat."

"That was good work," Logan said.

The smile faded. "An interesting way to usher in your stay."

Logan nodded. "Yes. Witnessing an accident like that."

"Accident," Rush repeated. "Another accident." For a moment, he appeared lost in thought. Then he brightened slightly. "I'm sorry you had to--well, to see me like that."

"You saved a life."

Rush waved a hand as if to deflect this. "Ever since that experience with my wife, I've been dealing solely with people who have cheated death. This is the first time I've had to deal with a life-or-death emergency since ... I guess since she was brought into the Providence ER. I didn't know it would affect me like that." He paused, then looked at Logan. "I wouldn't say this to anybody else, Jeremy, but I hope Porter Stone didn't make a mistake signing me up as chief medical officer."

"No mistake. Stone chose a fine doctor. And you wait and see: this will be the only medical crisis you'll face. From now on it'll be clear sailing. Now, how about a bite of lunch before I have to face this Tina Romero?"

Another, more genuine, smile crossed Rush's face. "Give me five minutes to finish up this report. Then I'm your man."

11.

Christina Romero's office was situated in Red, the container facility devoted to the med center and the various science labs. It reminded Logan more than a little of his own office back at Yale: orderly and clean, with row after row of books sorted by author and subject matter on long metal shelves. A large desk in the middle of the room was littered with artifacts and notebooks, yet somehow managed to look tidy; more artifacts were stored against the rear wall in a stack of carefully labeled plastic containers. Several diplomas and framed prints hung on the other three: a photo of an Egyptian wall painting; a print of Turner's Regulus, and--bizarrely--a very childlike depiction of the Sphinx.

If the office seemed vaguely familiar, however, Dr. Romero herself was a surprise. She was thin and very young--no more than thirty. Logan realized he'd been expecting a frowsy old woman in tweeds, a female Flinders Petrie. Romero could not have been more different. She was dressed in blue jeans and a black mock turtleneck with its sleeves pushed up to her elbows. She had kinky, shoulder-length black hair, parted in the middle, and it flared away from her face, looking not unlike the headdress of an Egyptian king. As Logan entered, she was seated behind the desk, absorbed in filling a fountain pen from a bottle of blue-black ink.

He knocked politely on the doorframe. Romero jerked in surprise, almost dropping the pen.

"s.h.i.t!" she said, grabbing for a tissue to wipe up the spilled ink.

"Sorry," Logan said, remaining in the doorway. "Get ink on yourself?"

"That's nothing," she said. "I might have ruined this." She held the pen up for him to see. "You know what this is? A Parker Senior Duofold in mandarin yellow, vintage 1927, the first year of production. Very scarce. Look--it even has the yellow threads on the barrel, before they switched to black." She waved it at him like a baton.

"Very impressive. Although I always preferred Watermans, myself."

She put the pen down and looked at him. "The silver overlays?"

"No. The Patricians."

"Oh." She screwed the cap onto the pen and slipped it into the pocket of her jeans, then stood up to shake his hand.

The handshake told Logan even more about Romero than the office decor did. He held her grasp just a shade longer than was typical.

"What do you want?" she asked. "I haven't seen you around before."

"That's because I just got here last night. The name's Jeremy Logan."

"Logan." She frowned.

"We have an appointment."

She brightened. "Oh, of course. You're the ghost--" She fell silent, but her green eyes twinkled with private amus.e.m.e.nt.

The same old silliness. Logan was used to it. "I prefer the term 'enigmalogist,' myself."

"Enigmalogist. Yes, that does lend an air of legitimacy." She looked him up and down, an expression on her face somewhere between skepticism and veiled hostility. "So--where is it? In that duffel bag you're carrying?"

"Where is what?"