The kid flew through the air and managed to perform an airborne spin into the swimming pool, drenching the barbecue and the deck along the back of the house. When Mark Zuckerberg and his friends weren’t sleeping, eating or hurling themselves from the zip line that ran across the pool, they were at the computers, coding away, working out the kinks, adding applications to Facebook.

It was the summer vacation of 2004, only months since Mark had created Facebook in his dorm at Harvard. He had moved with his tiny team of young programmers to a house on a quiet suburban street in Palo Alto, California, to be close to Silicon Valley.

The oversized living room looked like a mix between a dorm room and an engineering lab — and 24 hours a day, there was someone locked into one of the multiple laptops or desktops that were strewn about, wires curling everywhere like the entrails of a downed alien spacecraft. They’d picked up some whiteboards that were already covered with the scrawl of computer code in bright colours. The floor was littered with empty pizza boxes and beer cans. The soundtrack was a mix of alternative and hard rock.

Sean Parker — co-founder of Napster, the music-sharing site, and Mark’s new best friend since urging him out to California — was sleeping on a mattress in an empty corner, most of his belongings in storage. At 24, he was only four years older than Mark and the other kids, but he had already spent half a decade navigating the busts and booms of a newly re-emergent Silicon Valley.

To Sean the setup had a wonderful frat-house feel. The one person missing was Eduardo Saverin, Mark’s fellow Harvard student and founding partner. He had put up $1,000 to pay for Facebook’s first internet servers, according to Mark, and his money was financing the current operation. He was titular business head — yet he wasn’t involved in the day-to-day workings of Facebook, as far as Sean could see. Mark said Eduardo had gone to New York to pursue some sort of internship at an investment bank, which immediately set off warning bells in Sean’s mind.

Eduardo saw himself as a businessman, but Silicon Valley wasn’t about business; it was war. You had to do things that weren’t taught in any business class. Sean had never even gone to college; he’d started Napster while still in high school. Bill Gates had never graduated from Harvard. None of the true success stories out here had got where they were by taking classes. If you were going to do something like this — to really succeed — you had to live and breathe the project. Mark was living it. He was a genius with the unique focus to pull off something like this. Watching him program at four, five every morning, Sean had no doubt Mark had the makings of one of the truly great success stories in the modern, revitalised Silicon Valley.

Sean believed they could build this company into the billion-dollar project he’d been looking for. He was sure Facebook would trigger the billion-dollar payoff that had eluded him at Napster and his second start-up, Plaxo, another internet company. First, though, the kids could use a lesson in the finer points of life. If they were creating a premier social network, they should learn what it meant to be truly social. Mark, for all his geeky awkwardness, was going to become the toast of the town. Parties, fancy restaurants, girls — Sean could show him the way to all of it. He was a rock star in this town.

The plane was late because of heavy rain at JFK. Eduardo was going to get into San Francisco well past 10pm. Mark had said something about a party that Sean had got them invited to. It would be fun, but there’d also be the opportunity to meet investor types, including some venture capitalists — VCs — and even a few internet celebs.

According to Mark, Parker had already taken them to a handful of similar parties; over the past month since they’d hit California, they’d worked their way into the Stanford summer scene and the San Francisco high-tech groove, and had even made a few trips down to LA for high-profile Hollywood bashes. Eduardo couldn’t help but grow more concerned each time he heard about another milestone, party or dinner that he had missed. If Mark was thrilled that Eduardo had quit his New York internship on the first day and had made progress getting advertisers for Facebook, he certainly wasn’t showing it.

To be fair, Mark and his team were working round the clock at adding features to the site, and signing up more and more schools. At the rate they were going, they would surpass 500,000 members by the end of August — a pretty spectacular number. But with that incredible growth there came new problems. They were going to need more money soon: 500,000 users would burn a lot of server space. The company was still running on $18,000 Eduardo had deposited in a bank account; he’d given Mark blank cheques to draw on it. They’d soon have to hire real employees, get a real office, hire real lawyers.

Tonight’s party was at a club in a seedy stretch of massage parlours, cheque-cashing joints and fast-food restaurants. Eduardo saw a huge queue outside and a large man in a black suit with a headset by the door. The look on the man’s face as they approached said it all. It was San Francisco, sure, but even here there had to be standards. Eduardo gave their names and the man dutifully parroted them into his headset. Then he shrugged, surprised, and held open the door.

The place was dark and throbbing: two floors with low ceilings, flashing strobe lights and a Lucite stairway that curved above the bar to a raised VIP section. The music was blaring — a mix of alternative and dance — and waitresses in tiny skirts and midriff-baring tops pranced through the crowd, carrying trays stacked with brightly coloured martinis. The place was packed.

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