Dr. Mark Baker swept his straw-colored hair away from his eyes, then wiped his forearm across his brow. He wished the air-conditioning in the emergency room were better. Patients might complain that it was cool, but if you were hurrying from case to case for eight hours or more, it was easy to work up a sweat.

“Nobody move!”

Mark spun toward the doors leading to the ER, where a wild-eyed man pressed a pistol against a nurse’s head. She pushed a wheelchair in which another man sat slumped forward, his eyes closed, his arms crossed against his bloody chest. Dark blood oozed from beneath his splayed fingers and dropped in a slow stream, leaving a trail of red droplets on the cream-colored tile.

Behind them, Mark could see a hospital security guard sprawled facedown and motionless on the floor, his gun still in its holster, a crimson worm of blood oozing from his head. Mark’s doctor’s mind automatically catalogued the injury as a basilar skull fracture. Probably hit him behind the ear with the gun barrel.

The gunman was in his late twenties. His caramel-colored skin was dotted with sweat. A scraggly moustache and beard framed lips compressed almost to invisibility. Straight, black hair, parted in the middle, topped a face that displayed both fear and distrust. Every few seconds he moved the barrel of the gun away from his hostage’s temple long enough to wave it around, almost daring anyone to come near him.

The wounded man was a few years older than the gunman— maybe in his thirties. His swarthy complexion was shading into pallor. Greasy black hair fell helter-skelter over his forehead. His face bore the stubble of several days’ worth of beard.

“I mean it,” the gunman said. “Nobody move a muscle. My brother needs help, and I’ll kill anyone who gets in the way.”

Mark’s immediate reaction was to look around for the nearest exit, but the gunman’s next words made him freeze before he could act.

“You the doc?”

Now the gun was pointed at him. Mark thought furiously of ways to escape without being shot, but he discarded each plan as fast as it crossed his mind. “Yeah, I’m the doc.”

The gunman inclined his head toward the man in the wheelchair. “He’s . . . he’s been shot.” He snatched two ragged breaths. “I want you to fix him, pull him through.” He punctuated his words with rapid gestures from the pistol. “If he dies . . . if he dies, I’m going to kill everyone in here.” The gunman turned back toward his hostage. “Starting with her.”

Mark’s eyes followed the gun as it traversed once more from him to the nurse pushing the wheelchair. To this point his attention had been focused on the gunman, but now that he recognized the hostage, he knew the stakes were even higher. Although her red hair was disheveled, her normally fair skin flushed, there was no mistaking the identity of the woman against whose head the gunman’s pistol lay. The nurse was Kelly Atkinson—the woman Mark was dating.