the ground you walk on, Phil?"
Startled, Brinker jumped six inches in the air. "Jesus Christ!" He spun round. "Colonel, you pull that ghost act on me just one more time and I swear to God I'm gonna drop dead right in front of you! Then how would you feel?"
Smith laughed. "Sorry, I guess."
"Sure you would," Brinker grumbled. Then he brightened. "But since I'm not dead, despite your best efforts, you can take a look at what Ravi and I have cooked up today. Feast your eyes on the not-yet-patented Mark Two Brinker-Parikh nanophage, guaranteed to zap cancer cells, dangerous bacteria, and other internal nasties . . . most of the time, anyway."
Smith moved closer and studied the hugely magnified black-and-white image on the monitor. It showed a spherical semiconductor shell packed with an assortment of complex molecular structures. A scale indicator on one side of the screen told him he was looking at an assembly that was just two hundred nanometers in diameter.
Smith was already familiar with the Harcourt research team's general concept. Brinker and Parikh and the others were focused on creating medical nanodevices - their "nanophages" - that would hunt down and kill cancer cells and disease-causing bacteria. The interior of the sphere he was examining should be loaded with the biochemical substances - phosphatidylserine and other costimulator molecules, for example - needed either to trick the target cells into committing suicide or to mark them for elimination by the body's own immune system.
Their Mark I design had failed in early animal testing because the nanophages themselves were destroyed by the immune system before they could do their work. Since then Jon knew the Harcourt scientists had been evaluating different shell configurations and materials, trying hard to find a combination that would be effectively invisible to the body's natural defenses. And for months the magic formula had eluded them.
He glanced up at Brinker. "This looks almost identical to your Mark One configuration. So what have you changed?"
"Take a closer look at the shell coating," the blond-haired Harcourt scientist suggested.
Smith nodded and took over the microscope controls. He tapped the keypad gently, slowly zooming in on a section of the outer shell. "Okay," he said. "It's bumpy, not smooth. There's a thin molecular coating of some kind." He frowned. "The structure of that coating looks hauntinglv familiar . . . but where have I seen it before?"
"The basic idea came to Ravi here in a flash," the tall, blond-haired researcher explained. "And like all great ideas it's incredibly simple and freaking obvious ... at least after the fact." He shrugged. "Think about one particularly bad little mother of a bacterium - resistant staphylococcus aureus. How does it hide from the immune system?"
"It coats its cell membranes in polysaccharides," Smith said promptly. He looked at the screen again. "Oh, for Pete's sake . . ."
Parikh nodded complacently. "Our Mark Twos are essentially sugar-coated. Just like all the best medicines."
Smith whistled softly. "That is brilliant, guys. Absolutely brilliant!"
"With all due modesty, you are right about that," Brinker admitted. He laid one hand on the monitor. "That beautiful Mark Two you see here should do the trick. In theory, anyway."
"And in practice?" Smith asked.
Ravi Parikh pointed toward another high-resolution display - this one the size of a wide-screen television. It showed a double-walled glass box secured to a lab table in an adjoining clean room. "That is just what we are about to find out, Colonel. We have been working almost nonstop for the past thirty-six hours to produce enough of the new design nanophages for this test."
Smith nodded. Nanodevices were not built one at a time with microscopic tweezers and drops of subatomic glue. Instead, they were manufactured by the tens of millions or hundreds of millions or even billions, using biochemical and enzymatic processes precisely controlled by means of pH, temperature, and pressure. Different elements grew in different chemical solutions under different conditions. You started in one tank, formed the basic structure, washed away the excess, and then moved your materials to a new chemical bath to grow the next part of the assembly. It required constant monitoring and absolutely precise timing.
The three men moved closer to the monitor. A dozen white mice occupied the clear double-walled container. Half of the mice were lethargic, riddled with lab-induced tumors and cancers. The other six, a healthy control group, scampered here and there, looking for a way out. Numbered and color-coded tags identified each mouse. Video