I stood on the sidewalk beside a group of shirtless men shoveling gravel in the humid Saigon air. Their bodies were speckled with the suction-bruises of the ancient Chinese healing arts.

I was looking for a Mr. Tam, or "Tommy", a private guide recommended by the friend of a friend who had once made a business trip to Vietnam. At the time it hadn't seemed that important, and I had scribbled Tam's name and a vague set of Saigon directions on the back of an old envelope before going back to ordering iodine tablets and wrapping presents for the holidays I'd miss.

Now, standing on the corner beside a cardboard fish stall, "Tommy" seemed like a long-lost brother. He was the key to unlocking a secret journey, a dream that had carried me halfway around the world: to hike the thousand-mile Ho Chi Minh Trail, all the way from Saigon to Hanoi.

But finding Tam seemed suddenly more daunting than anything I might have to face in the weeks to come.

Two days and half a dozen cyclo drivers later I plunged into the maze of alleys and culverts of Tam's neighborhood. Children stopped playing ball to point and shout questions. Tam came stumbling out to greet me. His belt was unbuckled and his face bore the crinkly remnants of an afternoon nap but he stuck out a brisk hand and smiled without guile. He seemed almost as glad to see me as I was him.

"I want to hike to Hanoi," I told him in breathless Vietnamese, as the neighbors gathered. "Through the Central Highlands..." His smile never faltered. "No problem."

"Will you go with me?"

His handshake slowed perceptibly, then sped back up. "Yes."

The journey had begun.