After a long, busy day, Ralph Minker slides into the passenger seat of his wife's Saturn and leans back with a sigh as she pulls out of the parking lot.

His wife, Sandra O'Connell, glances over at him.

"Seat belt, please," she says gently, and Minker reaches over to grab it and snap himself in.

The exchange could be the reflective routine of a couple married for 25 years -- but it's also something more. Minker, 79, is in the middle stage of Alzheimer's disease, and O'Connell has just picked him up from the Herndon adult day-care program he attends two days a week.

Last week was an emotional one in the Minker-O'Connell household. The death of Ronald Reagan, who suffered for at least a decade with the brain-wasting disease, and the sight of the drawn face of Nancy Reagan, who cared for him throughout his illness, gave them a too-clear picture of the road they are heading down.

"That's where it ends up," said O'Connell, 63.

Minker's illness was diagnosed just a year after Reagan's but progressed more slowly. Though Reagan reportedly lost the ability to recognize even his wife, Minker still remembers much about his life -- his years in World War II as the youngest bomber pilot in his Army Air Forces squadron and the four decades he spent as a United Methodist minister in the Washington area.

But Alzheimer's is inexorably shredding those memories and making everyday life more and more difficult. Signing his name, dialing the phone, recalling the flowers he planted in the garden of their Reston home, the name (Blue Hen Chick) of the bomber he flew, remembering how to put on his pajamas -- such mundane things are fleeing in the face of the disease.

"It changes everything," he said, sitting at the kitchen table with a cup of yogurt in front of him, a slim man with warm blue eyes and a smile with a trace of sadness. A small sign on his left reminded him to "Take your pills!"

Like Reagan, Minker was an energetic, optimistic leader. In the same way that Reagan visited his office every day in the years immediately after his diagnosis, Minker, who retired from the ministry shortly before his diagnosis in 1995, stayed busy in the early stages of his disease.

With his wife, he organized his collection of World War II memorabilia and catalogued the 800 letters he and his family wrote each other at the time. (In one letter to his father, he described a bombing run as "a continuous surge between tense eager expectancy and weary monotony . . . a symphony in early morning shades of blue.")

Like Nancy Reagan, O'Connell has devoted the last several years to her husband's care.

But unlike the Reagans, Minker and his wife have not endured such a steep descent into illness. After eight years, Minker only recently moved into the middle stages of the illness. But now he is losing the ability to follow simple directions or complete simple tasks and needs almost constant supervision.

The relatively slow advance of Minker's illness -- "It's done less with me than to others that I know," he said -- is some comfort to him. But there are days he wonders "why in the hell I have to have it."

Before they had a name for what was wrong with him, O'Connell said she had begun to suspect that he had Alzheimer's, which afflicts about 4.5 million Americans. He was becoming confused while driving familiar routes around Fairfax County. He would forget that he had made a sandwich for lunch. Then, at dinner on a trip to Hawaii to celebrate their 15th wedding anniversary, Minker repeatedly asked his wife what they had ordered.

"And I knew," O'Connell said.

Shortly afterward, a neurosurgeon bluntly confirmed their suspicions. "Mr. and Mrs. Minker," he told them, "you have been dealt a very bad hand."

With that, O'Connell, who has a doctorate in behavioral science, embarked on a campaign to learn as much as possible about the disease. She read books, checked out the most recent research, studied nutrition and attended seminars by the National Capital Area Alzheimer's Association.

To keep Minker's brain as active as possible, the couple played Scrabble and other word games, did crossword puzzles and went to art galleries and baseball games. O'Connell laminated cards with photos of the flowers Minker had planted and quizzed him on them.

She also revamped their diet to focus on nutrition that some experts believe is beneficial to Alzheimer's patients: fruits and vegetables like strawberries, blueberries and red peppers, nuts, dark chocolate, no beef and a glass of red wine a day. They added vitamins to Minker's diet -- C, E and B complex -- and doctors added a mild antidepressant to help Minker cope with the sadness that can envelop him.

Minker also benefited from drugs that appear to help memory and thinking -- first Aricept and then Exelon -- though researchers believe they gradually lose their effectiveness over time.

But the disease put a quick end to the couple's retirement dreams. O'Connell, a business executive who designed and implemented computer systems for human resources departments, had planned to work a few years after her husband retired and then retire herself.

They talked about traveling the world, maybe living in England for a while. They wanted to spend time with Minker's grandchildren in Oregon. Minker volunteered at local charities. He wanted to expand his knowledge of wines. O'Connell planned to do more white-water rafting.

Instead, O'Connell cut back to part-time work in 1998 and then left her job four years ago. Now she consults to bring in income, but she is no longer comfortable leaving Minker home alone. He stopped driving in 2001, and they gave away his car shortly thereafter. He can't dial a phone anymore. He gave up his volunteer work.

In recent weeks, O'Connell quietly installed a bell on the front door that rings if it is opened so she knows when he leaves the house. She began cutting her husband's food -- out of sight so as not to embarrass him -- after he forgot how to use a knife.

Every time he arrives at a milestone like that, O'Connell said, "you grieve again."

Minker still reads the newspaper and watches the news, but O'Connell isn't sure how much he retains. He remembers Reagan as a "a good man in the government," but O'Connell said her husband, a devout liberal who went to seminary with Martin Luther King Jr., opposed many of Reagan's policies. As a minister, Minker was active in the civil rights movement and participated in the 1963 March on Washington. He preached against the Vietnam War and, in the 1970s, was one of the first clergymen in the area to welcome gay men and lesbians to his church.

"The hardest thing for Ralph has been the loss of meaningful activity," his wife said. "He's so used to being a contributor, and I wonder if Reagan didn't feel that, too -- when you're so used to contributing and then to have that taken away."

The couple stays active, attending church weekly, going on walks, seeing friends. Baseball games are too much for him now, but they still take Minker's World War II collection to local schools, although O'Connell does most of the talking.

Meanwhile, four men from their church come over regularly to give O'Connell a breather. Minker has a weekly lunch with a friend, and O'Connell takes yoga classes and sees a therapist to cope with the stress and grief. She tries not to think about "if only," but a sharp stab of envy sometimes comes when she hears friends talk about cruises or time spent with grandchildren.

After the diagnosis, O'Connell quickly arranged their financial affairs to give her control over them, but she worries that their savings won't cover the tens of thousands of dollars annually that 24-hour care would cost. But she tries not to focus on the inevitable, hoping that Minker's decline will continue its creep.

"I'm just not ready to think about the next stage," she said in a whisper. "It's a place where I don't want to go."

But Minker has.

The disease, he said, "is just as I saw the war: Nobody could stop the guns, and nobody can stop the Alzheimer's -- yet." He paused a moment over his yogurt. "Someday, maybe."