Reason says that AIDS appears to be the work of an infectious agent that can be transmitted sexually, perhaps by blood, or by contact between parent and child. There is no evidence that AIDS can be spread by casual encounters or through the air. And in the two years since the disease was first officially reported, not a single health-care worker has caught the illness from a patient.

Fear says that AIDS may lurk inside a victim for from six months to two years before the onset of symptoms. And during this time the victim can infect others. An airline pilot who shuttled between New York and Los Angeles apparently passed the illness on to four lovers in each city. In a three-month period, all eight lovers died.

And reason says that those who are not in fact seriously threatened should not let panic add to the sufferings of those who are already affected by the disease itself. Not one of the hundreds of doctors who are studying AIDS has suggested that we are facing some twentieth-century version of the Black Death. Yet, as imaginations have become infected with fear, paranoia, and superstition, AIDS victims have been fired from their jobs, driven from their homes, and deserted by their loved ones. Any homosexual or Haitian has become an object of dread. And New York in 1983 has become a place where a woman telephones Montefiore Medical Center and asks if her children should wear gloves on the subway.

One moment there is idle chatter about the Yankees or the new Lucas film. And then, suddenly, fear and reason are grappling with the specter of this fatal illness for which there is no cure.

One of those who witnessed the first stirrings of this fear was a 28-year-old AIDS victim named Michael Callen. He comes from a section of Ohio where homosexuality is considered at best a crime against nature. He was raised a Methodist, and he sang in the church choir. He remembers that he often prayed for relief from his sexual urges.

"I was tortured over my gayness," Callen says. "I used to pray, 'Please, if you'll just take it away, I'll be wonderful.' "

There was no divine intervention, and Callen began reading all he could about sex. One writer suggested that homosexuals tend to congregate in bowling alleys. "I started driving around to every bowling alley I could find, all to no avail," Callen says. When he was seventeen, he traveled east to pursue a singing career. After an audition, he needed to use a rest room. The nearest facility was full, so Callen went to the one on the floor above. He saw a group of men lounging by the stalls for a purpose he intuitively understood.

“I thought, ‘I am home, there are others like me,’” Callen said.

Over the next year, Callen pursued his sex life in toilet stalls, referred to as “tearooms.” He remembers, “It was smelly and sordid and dirty, and I thought, ‘This is my life.’ ” One day, a man slipped Callen a note written on a sheet of toilet paper. The note asked if they had met at the baths. Callen took another sheet of toilet paper and scribbled a message asking, “What are the baths?” The man wrote back, “Are you serious? Meet me outside.”

Soon, Callen was going to the baths every other day. There were no windows. There were no clocks. There was no music. There was only continuous, impersonal sex, often with men whose early lives had been as tortured as his own. “I was lonely and horny,” he says. “I was going to prove my parents wrong.” He had sex with hundreds of men before he had his first romantic affair, a passionate relationship with a police officer that shattered after a year. On a Christmas Eve, Callen ended up back at the baths, singing carols.

During his encounters at the baths, one infection after another invaded Callen’s body. He then passed the infections on to other men, who in turn passed them to still others. The medical charts of the men in the baths began to read like something out of Biafra. In 1979, Dr. B.H. Kean, of the New York Hospital-Cornell Medical Center, called the baths a public-health threat. Kean wrote, “The patient would be treated for a second, third, fourth, and fifth time…. The patient has been infected again and again on a monthly basis.” The baths stayed open. And whenever Callen fell ill, there was always a pill or a shot that would allow him to return to the cubicles.

Then out of the swarm of microbes there appeared something that eluded all of the medications and was able to subvert the trillion-plus cells of the immune system. This was most probably a virus, bits of DNA coated with protein. While Callen coupled in the baths, the bits of DNA slipped into his blood cells and took over the reproductive machinery. More bits of DNA were produced, and more cells were invaded. After a time, Callen’s immune system became a junkyard. He began suffering fatigue and swollen glands. Finally, in December of 1981, he went to Dr. Joseph Sonnabend for a blood test.