THE DAVID KELLY AFFAIR.

Shortly after 3 p.m. on Thursday, July 17, 2003, David Kelly, a fifty-nine-year-old scientist employed by the British government, walked out of his house in Southmoor, a small village ten miles southwest of Oxford. Kelly, a slight, wiry man, with thinning gray hair, glasses, and a beard, lived with his wife, Janice, in a handsome stone cottage that sits on about half an acre of land at the western edge of the village, opposite the Wagon & Horses pub. He crossed the road and headed up a bridle path that goes by the pub's car park. It was a warm day, but he was wearing a thick blue jacket, hiking boots, and jeans. The path leads north, past some fields where, a couple of months previously, Kelly and one of his three daughters, Rachel, had spotted a newborn foal. They had arranged to go and see how the foal was doing that evening.

Kelly had a lot on his mind. Two days before, he had been questioned at a televised hearing of the House of Commons Foreign Affairs Committee about an unauthorized interview he had given to a BBC journalist in May. His employer, the Ministry of Defence, had told him that it wouldn't take any disciplinary action, but Kelly, a deeply private man, had found the publicity excruciating. He was also getting ready to join the Iraq Survey Group, a team of American, Australian, and British experts who are searching for Saddam Hussein's weapons of mass destruction. He was due to depart for Baghdad in eight days.

After crossing the A420, the main road between Oxford and Swindon, Kelly carried on to the neighboring village of Longworth, where he ran into a neighbor, Ruth Absalom, who was walking her dog, Buster. Absalom, an elderly woman with white hair and a thick rural accent, asked Kelly how he was. "Not too bad," he replied. They chatted for a few minutes. Buster was pulling on his leash, and Kelly told Absalom he had to be getting along. "Cheerio, Ruth," he said.

Kelly and his wife were well liked locally, but most of his neighbors weren't fully aware of what he did for a living. For almost twenty years, he had been one of the British government's leading experts in chemical and biological warfare. During the nineteen-nineties, he had served as a United Nations weapons inspector in Iraq, and in 1996 the Queen had made him a Companion of the Order of St. Michael and St. George, an official honor that ranks just below a knighthood.

Kelly kept walking. On the northern side of Longworth, a tree-lined lane runs through a pretty valley to Harrowdown Hill, a local landmark that affords magnificent views of Oxfordshire. Kelly sometimes walked well beyond the hill, but his wife was expecting him home soon. Janice Kelly suffers from arthritis, and when Kelly left she was lying down, because she wasn't feeling well. Reaching a dense wood at the top of the hill, Kelly headed into the trees. After about fifty or sixty yards, the way was blocked by thick bramble bushes and other undergrowth. In a small clearing, he sat down with his back against a tree. In the pocket of his jacket he was carrying a cell phone, some of his wife's painkillers, and a lock knife that he usually kept in his desk drawer. He had almost complete privacy. The area attracts ramblers, but it was a weekday afternoon, and few people were about.

Between 5 p.m. and 6 p.m., two of his colleagues at the Ministry of Defence called his cell phone. Kelly didn't answer. At some point, he removed his spectacles and put them in his pocket. He got out the painkillers, swallowed more than twenty of them, and washed them down with some Evian water he was carrying. After waiting for them to take effect, he held the knife, which had a three- or four-inch-long blade, and slashed at his left wrist. The first incisions were shallow--the kind of cuts that pathologists refer to as "hesitation marks." With blood running down his arm, Kelly took off his watch and laid it on the ground, then cut deeper, severing the ulnar artery, which runs along the left side of the wrist. Within minutes, he was dead.

In early September last year, Prime Minister Tony Blair made a visit to his parliamentary constituency, Sedgefield, a small town in northeast England. During the flight from London, Blair talked with Alastair Campbell, his longtime press secretary and strategist, about the need to persuade a skeptical British public that Saddam Hussein represented a serious danger, and that he had to be confronted. The previous week, Vice-President Dick Cheney had called Saddam a "mortal threat." Blair was scheduled to visit President George Bush at Camp David later in the month, a meeting that the British papers were already billing as a war summit.