Fantastic Voyage - By Isaac Asimov Page 0,43

heartbeat will be right behind us and when it comes ..."

"If it comes," said Owens softly.

"When it comes," repeated Michaels, "there'll be a terrific surge of blood. We'll have to stay as far ahead of it as possible."

With determined desperation, Owens flashed the ship ahead for the tiny opening that marked the center of, the crescent crack ("semi-lunar" for that reason) that marked the closed valve.

The operating room labored under a tense silence. The surgical team, hovering over Benes, were as motionless as he. Benes' cold body and stopped heart brought the aura of death close above all in that room. Only the restlessly quivering sensors remained as signs of life.

In the control-room, Reid said, "They're obviously safe so far. They're through the tricuspid and are following a curved path aiming at the semi-lunar valve. That's deliberate, powered motion.

"Yes," said Carter, watching his stop-watch in tense agony. "Twenty-four seconds left."

"They're almost there now."

"Fifteen seconds left," said Carter inexorably.

The heart-technicians at the electro-shock apparatus moved stealthily into position.

"Aiming straight into the semi-lunar valve." "Six seconds left. Five. Four . . ."

"They're going through." And as he spoke, a warning buzzer, ominous as death, sounded.

"Revive heartbeat," came the word over one of the speakers, and a red button was pressed. A pace-maker went into action, and a rhythmic surge of potential made its appearance on an appropriate screen in the form of a pulsing swing of light.

The oscilloscope registering heartbeat remained dead. The pace-maker pulse was increased, while eyes watched tensely.

"It's got to start," said Carter, whose whole body tensed and pushed forward in muscular sympathy.

The Proteus entered the aperture, which looked like a pair of barely open lips curved in a gigantically pendulous smile. It scraped against the tough membrane above and below, hung back a moment as the engine roar raised its pitch in a temporarily vain attempt to free the ship of the sticky embrace-then lunged through.

"We're out of the ventricle," said Michaels, rubbing him forehead and then looking at his hand which had come away wet, "and into the pulmonary artery. -Continue at full speed, Owens. The heartbeat should start in three seconds."

Owens looked back. He alone could do so, the others being strapped helplessly in their seat with forward vision only.

The semi-lunar valve was receding, still closed, with its fibers straining their points of attachments into suckers of tense tissue. With distance, the valve grew smaller, and was still closed.

Owens said, "The heartbeat. isn't coming. It isn't . . . Wait, wait. There it is." The two leaves of the valve were relaxing; the fibrous supports were falling back and their tense roots puckered and became flabby.

The aperture was gaping, the rush of blood was coming, and overtaking them was the gigantic "bar-room-m-m" of the systole.

The tidal wave of blood caught up with the Proteux, hurtling it forward at break-neck velocity.
Chapter 11 : CAPILLARY
The first heartbeat broke the spell in the control-tower. Carter raised both hands in the air and shook them in mute invocation of the gods. "Made it, by thunder. Brought them through!"

Reid nodded. "You won that time, general. I wouldn't have had the nerve to order them through the heart."

The whites of Carter's eyes were bloodshot. "I didn't have the nerve not to order it. Now if they can hold up against the arterial flow . . ." His voice rang out into the transmitter. "Get into touch with the Proteus the moment their speed diminishes."

Reid said, "They're back in the arterial system, but they're not heading for the brain, you know. The original injection was into the systemic circulation, into one of the main arteries leading from the left ventricle to the brain. The pulmonary artery leads from the right ventricle-to the lungs."

"It means delay. I know that," said Carter. "But we still have time." He indicated the Time Recorder, which read 48.

"All right, but we'd better switch the point of maximum concentration to the respiration center."

He made the appropriate change and the interior of the respiration post was visible on the monitor screen. Reid said, "What's the respiration rate?"

"Back to six per minute, colonel. I didn't think we were going to make it there for a second."

"Neither did we. Hold it steady. You're going to have to worry about the ship. It will be in your sector in no time."

"Message from the Proteus," came another voice. "ALL WELL. Uh, sir? There's more, do you want it read?"

Carter scowled. "Of course, I want it read."

"Yes, sir. It says: WISH YOU WERE HERE AND