Jack tightened the jib sheet, his sunburned arms gleaming with sweat as he strained against the crank. With a satisfying whomp sail went taut, and Sanneke heeled leeward, her bow suddenly slicing faster through the muddy waters of Galveston Bay. He had the Gulf of Mexico behind him, had sailed around Point Bolivar earlier that afternoon, dodging the ferry from Galveston Island, and was now tacking past the string of refineries on the shores of Texas City as he sailed north toward Clear Lake. Toward home.

Four days at sea on the Gulf had turned him brown and shaggy.

He had informed no one of his plans, had simply stocked up on food and set sail toward open water, beyond sight of land, into nights black his eyes had been dazzled by the stars. Lying on his back on deck, the Gulf waters gently rocking the hull beneath him, he’d gazed for hours at the night sky. With that field of stars stretching in every direction, as far as he could see, he could almost imagine Emma was hurtling through space, that each rise of the swells was thrusting him deeper into the coil of another galaxy. He had emptied his mind of everything but the stars and the sea. Then a meteor had streaked by in a brilliant slash of light, and suddenly he’d thought of Emma. He could not put up barricades high enough to keep her out.

She was always there, hovering at the edges, waiting to slip into thoughts when he least expected it. Least wanted it. He had gone rigid, his eyes fixed on that dying streak of the meteor’s trail, even though nothing else had changed, not the direction of the nor the rise and fall of the swells, he had felt suddenly, deeply, alone.

It was still dark when he’d raised the sails and turned back for home.

Now, as he motored up the channel into Clear Lake, past rooflines silhouetted against the glare of sunset, he regretted decision to return home so soon. On the Gulf there had been a constant breeze, but here, the heat hung unstirred and the was stifling.

He tied up at his slip and stepped onto the dock, his legs unsteady from days at sea. First order of business, he thought, a cold shower. He’d save the boat cleanup for tonight, when it was cooler. And as for Humphrey, well—another day in the kennel wouldn’t hurt the little hair ball.

Lugging his duffel bag, he up the dock and was walking past the marina’s small grocery store when his gaze fell on the newsstand. His duffel bag slipped from his grasp and hit the ground. He stared at the banner headline across that morning’s Houston Chronicle, “Emergency Shuttle Countdown Begins—Liftoff Tomorrow.” What has happened? he thought. What has gone wrong?

With shaking hands he pulled quarters from his pockets, fed the coins into the slot, and grabbed a copy from the stand. Two photos accompanied the news article. One was of Kenichi Hirai, the NASDA astronaut from Japan. The other was of Emma.

He snatched up the duffel bag and ran for a phone.

There were three flight surgeons at the meeting—an indication to Jack that the crisis they faced was medical. As he walked into the room, heads turned in surprise. He read the unspoken question in space station flight director Woody Ellis’s eyes, What’s Jack McCallum doing back in the fold?

Dr. Todd Cutler gave the answer. “Jack helped develop our emergency medical procedures protocol for the station’s first crew. I thought he should join us.” Ellis said, uneasily, “The personal angle makes this complicated.” Emma was what he meant.

“Every member of that crew is like family to us,” said Todd. “So in a way, it’s all personal.” Jack took a seat beside Todd. Sitting at the table were the NSTS deputy director, the ISS mission operations director, flight surgeons, and several program managers. Also present was NASA’s public affairs officer, Gretchen Liu. With the exception of days, the news media largely ignored NASA operations. Today, though, journalists from every news agency were crammed into the tiny pressroom in NASA’s Public Information building, awaiting Gretchen’s appearance.

What a difference a day made, thought Jack. Public attention was fickle.

It demanded explosions, tragedy.

Crisis. The miracle of a flawless operation drew no one’s attention.

Todd passed a sheaf of papers to him, with a note scrawled on top, “Hirai’s labs and clinical findings last 24 hours. Welcome back.” Jack flipped through the medical reports while he listened to the meeting. He had a day’s worth of developments to catch up on, and it took him a while to absorb the essentials. Astronaut Hirai was seriously ill, his lab findings puzzling to everyone. shuttle Discovery was poised for a six A. M. EDT launch manned by Kittredge’s crew, along with an astronaut-physician. Countdown was on schedule.

“Any change in your recommendations?” the NSTS deputy director asked the flight surgeons. “Do you still think Hirai can wait for a shuttle evac?”

Todd Cutler answered. “We still believe a shuttle evac is the safest option. We aren’t changing our recommendations in that regard. ISS is a fairly well-equipped medical facility, with all drugs and equipment needed for cardiopulmonary resuscitation.”

“So you still believe he’s had a heart attack?”

Todd looked at his fellow flight surgeons. “Frankly,” he admitted, “we’re not entirely certain. There are things that do point to myocardial infarction—a heart attack, in layman’s terms. Mainly, the rising levels of cardiac enzymes in his blood.”

“Then why are you still unsure?”

“The EKG shows only nonspecific changes—a few T wave inversions. It’s not a classic pattern for an MI. Also, Hirai thoroughly screened for cardiovascular disease prior to his in the program. He had no risk factors. Frankly, we’re not sure what’s going on. But we do have to assume he has had a heart attack. Which makes a shuttle evac the best option. It’s a reentry and a controlled landing. Far less stress on the patient coming home in the CRV. In the meantime, ISS can deal with any arrhythmias he may have.”

Jack looked up from the lab reports he’d been scanning. “Without the necessary lab equipment, the station can’t fractionate CK levels. So how can we be sure this enzyme is really from the heart?” Every one’s attention turned to him.

“What do you mean by ‘fractionate’?” asked Woody Ellis.

“Creatine kinase is an enzyme that helps muscle cells utilize stored energy. It’s found in both striated and cardiac muscle. If there’s damage to heart cells, say, in a heart attack, the CK rise in the blood. That’s why we’re assuming he had a heart attack. But what if it’s not the heart?”

“What else could it be?”

“Some other type of muscle damage. Trauma, for instance, or convulsions. Inflammation. In fact, just a simple intramuscular injection can cause the CK to rise. You need to fractionate the CK order to tell if it’s from heart muscle. The station can’t do that test.”

“So he may not have had a heart attack at all.”

“Correct. And here’s another puzzling detail. After acute muscle damage, his CK levels should drop back to normal. But look at the pattern.” Jack flipped through the lab sheets and read off the numbers. “In the last twenty-four hours, his levels have been steadily rising. Which indicates continued damage.”

“It’s just part of the bigger puzzle,” said Todd. “We’ve got abnormal results all over the board, without any recognizable pattern. Liver enzymes, renal abnormalities, sedimentation rate, blood cell counts. Some labs go up while others are dropping. It’s as though different organ systems are taking turns being attacked.

Jack looked at him. “Attacked?”

“Just a figure of speech, Jack. I don’t know what process we’re dealing with. I know it’s not lab error. We’ve run controls on other crew members, and they’re perfectly normal.”