"I wasn't as committed to ending my life as I thought when I got to the edge of the water," he said. "If I wasn't such a coward, I would have used a gun. But you know what stopped me? I said: 'Somebody is going to have clean this up.' I didn't want anybody to clean up after me. I wanted to go quietly."
These days, Mr. Horner, 37, is anything but quiet about AIDS. Two years ago, he started the Black Educational Aids Project, using his own money and 5,000 brochures. Since then he has given dozens of lectures in Baltimore, trying to impress on people the need to protect themselves.
Watching him speak in a West Baltimore church basement, you can see the polish and poise that carried him through the Wharton School of Business and into corporate America. He moves with a self-assured ease that belies the urgency of his message.
"The one key, the one tool against HIV is education," he says. "We have to see our own face. Only then will we be responsible for our own behavior and protecting ourselves from risk."
He is passionate about this. He wants to make people understand because, nine years ago, he ignored warnings about HIV and AIDS.
"Even though I was very knowledgeable of the disease, I had seen it as a gay white disease and me not being gay or white, I didn't think it could affect me," said Mr. Horner.
Since then, the virus has taken its toll. You can see it in the way his belt is pulled tightly over the loose waistband of his pants, in the pain that flashes through his eyes after sudden moves. The virus has also turned this once-self-involved black professional into a missionary who will go anywhere to talk about the AIDS virus -- a living room, classroom, city market or church basement. All he needs is an invitation.
"AIDS is the best thing that happened to me," he said. "I say that because it put me in a position where I had to realize there was more to life than what I thought. It's not about money. It's not about power. It's not about position, because I had all of that."
He used to be a purchasing manager for Pennwalt, a chemical products firm in his hometown of Philadelphia. In those days, when he had access to a corporate jet and a bottomless expense account, he was so far removed from the world of HIV and AIDS he might as well have been on another planet. Then came the troubling illnesses, the weakness, the bad news. Once, while living in Washington, he turned on the gas in his apartment and lay down, inviting death.
In 1989, he quit his job and came to Baltimore, the only town where he had friends who would take him in. His family, which has since accepted his disease, initially rejected him. He fought depression and suicidal impulses, finding strength in religion.
His newest AIDS awareness effort, begun last year, is called Churches United Against AIDS. Mr. Horner wanted to reach more people and to involve the black religious community. He quickly learned that most churches were not eager to join his cause. Pastors refused to listen to him. He kept making phone calls and writing letters. He knew that nothing would happen without a minister's help.
"It must start with him because each church is a fiefdom and every pastor is king, whether he has one member or 10,000," said Mr. Horner, who in some cases waited months.
"It takes a lot of patience. Ah man, I've read the Book of Job a hundred times," he said, adding that each engagement, whether in a church or a city market, is a success. "I don't go to a presentation where I don't have someone who comes up and says: 'I had a son who died of AIDS. My brother died of AIDS.'
Everybody has a story."
Yvonne Leacock, who coordinates an AIDS ministry for Heritage United Church of Christ, is one of many who have joined Mr. Horner's cause.
"He has such vision and drive," she said. "He's really great to work with."
On some days, Mr. Horner's pace becomes too much, and he takes to his bed. But at least now he sleeps in his own bed, in his own apartment. He spent part of last year in a group home. He says determination, faith and medication brought him out of the home. Now he lives on West North Avenue, drawing strength from his religion and his mission.
"This is my life now," he said. "I was focused on money and having fun. My life is more fulfilling now than when I was making $100,000 a year."