I’m in Khartoum, Sudan, in a shabby hotel room with Idriss Anu and Daoud Hari. Their eyes are wide with fear. They want to be anywhere but here. Idriss is a driver and Daoud, an interpreter-guide. The two have just spent five weeks imprisoned in Darfur with Paul Salopek—the writer who hired them while on assignment for National Geographic—because they illegally crossed the border from Chad to Sudan. After intense negotiations, all were released from jail; now Paul is on his way back to the United States. But what about Idriss and Daoud? I’ve promised Paul I’ll get them home safely, but it won’t be easy.

Daoud Hari (left) and Paul Salopek (center) were imprisoned in Sudan.

The Sudanese rebels who arrested them confiscated their identity papers. A U.S. Embassy official explains that a diplomat from Chad will arrive to help with the papers. We’ll need more than that, I think. We’ll need a miracle. That miracle appears in the form of dedicated diplomats from Chad and the U.S. Embassy. Two days later Idriss and Daoud fly home.

Paul took a risk when he crossed Sudan’s border. He paid dearly. He didn’t want to break the law, but felt there was no other way to tell this story, because the Sudanese authorities keep Darfur and its war off-limits to journalists. Those who help and guide us in dangerous, unfamiliar places are the often unsung heroes behind the work of any writer or photographer. Idriss and Daoud also took a risk and paid the price. They, too, wanted the story told.

Photograph by Candace Feit

My father and I are saying goodbye at a small airport in southern Africa. He and close friends of his have joined me in one of my favorite places, Botswana's Okavango Delta. We've always been close, but for some reason he seems especially emotional as I put him on the plane. Tears well in his eyes as he says how much he loves me and hopes we'll see more of each other. I assure him that I'll be home soon. He smiles and climbs into the plane.

Immediately I call my mother and sister and tell them that something is not right. During our safari he became easily confused. He drifted off in conversations. He seemed disengaged. One evening as we talked, Dad—a world traveler and geography whiz—couldn't remember the name of the Swiss village he and my mother stayed in at least a dozen times.

My mother takes him to a neurologist for testing. The diagnosis is dementia, most likely Alzheimer's. Dad remains cheerful and positive. As often happens in these cases, my mother is the one who struggles with despair. Shortly thereafter, she is diagnosed with cancer. Six months later, she is gone.

My sister and I face the toughest decision of our lives: How to give our father the care he deserves? We find an excellent facility, three miles from my sister's home, that specializes in caring for those with dementia. At first he resists, then settles in. When I call, my father tells me he's buying a new yellow Mustang, and that he and my mother are driving over to visit this afternoon. It breaks my heart to hear his gentle voice making plans that will never happen, but then I think that if he is happy living in an imaginary world with his beloved wife, perhaps memory loss isn't such a bad thing. I accept his illness and cherish every moment with him.

Memory, perishable and enduring, is the brain's archive. It is a marvel of neuronic circuitry, as Joshua Foer explains in this month's cover story. Its loss can be cruel, but remember this: It is through memory that we hold on to those we love.