For 17 months, they tracked one another’s movements like prey.But Senators Barack Obama and Hillary Rodham Clinton came together here on Thursday evening to pull off a secret rendezvous. They ditched their traveling entourages, eluded camera crews across town and startled many of their own advisers as they held their first private meeting since becoming archrivals for the Democratic presidential nomination.It was a political scavenger hunt like this capital had seldom seen before — at least in the current frenzied climate — where the two rivals huddled at an undisclosed location. Only hours earlier, she sought to cool speculation that she was clamouring to be his running mate, but suddenly the city’s media was awash in rumor as word spread of their meeting.The evening began in routine fashion, with Obama holding a large rally in northern Virginia. Then, he was scheduled to travel by motorcade to Dulles International Airport and fly to Chicago. The motorcade arrived, but Obama did not, stirring alarm among reporters who had been aboard the campaign plane for 45 minutes as it sat on the tarmac.Shortly before takeoff, one part of the secret was divulged. Robert Gibbs, the campaign’s communications director, said Obama would not be flying to Chicago as previously scheduled. He gave no reason for this mysterious pronouncement and there was little time for questions, considering that the engines had started to whir.Sunlen Miller, who covers the Obama campaign for ABC News, filed an urgent dispatch via Blackberry to report that the senator had abruptly changed plans and had given the slip to those who were traveling with him all day. “I sent it as the wheels were going up,” Miller said of her message, recounting the agitation and confusion among her fellow travelers as the 757 lifted off.It wasn’t until after the plane landed in Chicago — sans the presidential candidate — that Gibbs confirmed a meeting had taken place between the rivals. Details? None given.The face-to-face meeting, initiated by Clinton, illustrated how the hierarchical roles of the candidate’s relationship suddenly were changing. While Obama agreed to meet Clinton on her terms — at the location and time of her choosing — he was doing so wearing the title of a presumptive nominee, eager to get their first session out of the way and move onto the general election.Several early reports suggested that Obama and Clinton were holding the secret session at her home on Whitehaven Street, which sits in the shadow of the vice president’s residence in Northwest Washington. In the end, aides said, the meeting did not take place there, a development that for hours injected a cloak-and-dagger-like element into the drama and set off a mad scramble for reporters to find the secret location.For a time, the search took place live on cable television, unfolding like a Washington spy thriller, with the two leading characters sneaking around with the help of decoys and diversions. Questions went largely unanswered. Advisers to both candidates did not respond to questions by telephone or email. Throughout the long primary season, Chuck Todd, the political director of NBC News, turned to maps and charts to help explain the state-by-state — and delegate-by-delegate — manoeuvreings. No visual aids could help explain this mysterious Clinton-Obama story.Finally, as Obama was headed back to Chicago on a private plane and Clinton had returned to her home, another rarity took place. A joint statement was issued by representatives of the two senators, but sent out by Obama’s staff. Those words, perhaps, were the first cooperative undertaking since the presidential race began six seasons ago.“Senator Clinton and Senator Obama met tonight and had a productive discussion about the important work that needs to be done to succeed in November,” the statement said.Clinton’s farewell from the race is on Saturday.