WITHOUT ANY particular pride, John thought his lab in the basement of the Ballard house a marvel of ingenuity.  The centrifuge that he had improvised out of tire-balancing equipment had cost less than a thousand dollars.  His freezer was stock home bar equipment turned on its back and with a calibrated thermostat added.  It was accurate to within one degree Centigrade.  He had improvised peristaltic pumps from scuba equipment.  His cell disrupter was adapted from a used yachting sonar.  The electron microscope, a dual-stage thirty Angstrom resolution ISI model, cost him the most time and considerable money.  It was provided as a consignment-theft item by the San Francisco underworld at a cost of twenty-five thousand dollars.

And so it went with the entire lab.  He fashioned the negative-pressure research rooms out of plywood and plastic film.  The airlock was sealed by two small-boat hatches, which forced him to crawl into and out of the rooms.  It was the only major inconvenience.

Before the lab was completed, John was at work with his computer, setting up the full-color graphics of the molecular models upon which he would center his attention.  In parallel computer storage circuits, he filed away everything he could ferret out about the ways existing drugs functioned in the body.  He paid particular attention to known data on enzymes and specific DNA receptors.

It gratified him to discover that many of the most important requirements for his molecular maps were available in "canned" form - on computer discs or in storage programs that could be bought or stolen.  By the time the lab was completed he had his computer loaded with the elemental building blocks of his project.

There was a hypnotic fascination in sitting before the chathode display, watching the double spirals of the primal helix turn and twist at his command.  The red, green, purple and yellow lines took on a life of their own.  His mind and the display fell into a kind of unified space within which it was difficult to separate which was in his mind and which in the screen.  It seemed at times as if his hands on the computer controls created the images in his head, or the image would be in his head and then appear as if miraculously on the screen.  There were moments when he thought he was actually speaking in the language of the genetic code, talking to specific sites on DNA molecules.

During these periods, the actual flow of time vanished from his consciousness.  On one occasion, he crawled from the airlock hatch, staggered to his feet and found it just dawn outside.  Investigation revealed that he had been working steadily for thirty-seven hours with only an occasional sip of water.  He was achingly hungry and his trembling hands could not even deal with solid food until he drank almost a full quart of milk.

The structure he needed to see and understand was slowly revealing itself, though, both on the screen and in the computer-monitored outputs of his lab.  He knew it was only a matter of time until he fitted the proper molecular key into the biological lock.  The answers were here in the lab and in his head.  They merely had to be opened out into their own reality.  The nucleotide sequences of the DNA encoded all of the genetic information for every biological function.  It was a code-breaking problem.