"Any particular reason for the choice?"

"It seems," Leavitt said, "that the Navy sponsored some studies a few years back on the psychological effects of colored environments. Those studies have been applied here."

They came to Immunization. A door slid back revealing three glass booths. Leavitt said, "Just sit down in one of them."

"I suppose this is automatic, too?"

"Of course."

Hall entered a booth and closed the door behind him. There was a couch, and a mass of complex equipment. In front of the couch was a television screen, which showed several lighted points.

"Sit down," said a flat mechanical voice. Sit down. Sit down."

He sat on the couch.

"Observe the screen before you. Place your body on the couch so that all points are obliterated."

He looked at the screen. He now saw that the points were arranged in the shape of a man.

He shifted his body, and one by one the spots disappeared.

"Very good," said the voice. "We may now proceed. State your name for the record. Last name first, first name last."

"Mark Hall," he said.

"State your name for the record. Last name first, first name last."

Simultaneously, on the screen appeared the words:

SUBJECT HAS GIVEN UNCODABLE RESPONSE

"Hall, Mark."

"Thank you for your cooperation," said the voice. "Please recite, 'Mary had a little lamb.' "

"You're kidding," Hall said.

There was a pause, and the faint sound of relays and circuits clicking. The screen again showed:

SUBJECT HAS GIVEN UNCODABLE RESPONSE

"Please recite."

Feeling rather foolish, Hall said, "Mary had a little lamb, her fleece was white as snow, and everywhere that Mary went, the lamb was sure to go."

Another pause. Then the voice: "Thank you for your cooperation." And the screen said:

ANALYZER CONFIRMS IDENTITY

HALL, MARK

"Please listen closely," said the mechanical voice. "You will answer the following questions with a yes or no reply. Make no other response. Have you received a smallpox vaccination within the last twelve months?"

"Yes."

"Diphtheria?"

"Yes."

"Typhoid and paratyphoid A and B?"

"Yes."

"Tetanus toxoid?"

"Yes."

"Yellow fever?"

"Yes, yes, yes. I had them all."

"Just answer the question please. Uncooperative subjects waste valuable computer time."

"Yes," Hall said, subdued. When he had joined the Wildfire team, he had undergone immunizations for everything imaginable, even plague and cholera, which had to be renewed every six months, and gamma-globulin shots for viral infection.

"Have you ever contracted tuberculosis or other mycobacterial disease, or had a positive skin test for tuberculosis?

"No."

"Have you ever contracted syphilis or other spirochetal disease, or had a positive serological test for syphilis?"

"No."

"Have you contracted within the past year any gram-positive bacterial infection, such as streptococcus, staphylococcus, or pneumococcus?"

"No."

"Any gram-negative infection, such as gonococcus, meningeococcus, proteus, pseudomonas, salmonella, or shigella?"

"No."

"Have you contracted any recent or past fungal infection, including blastomycosis, histoplasmosis, or coccidiomycosis, or had a positive skin test for any fungal disease?"