Creator Doug Ellin has a pithy answer to the question of what Entourage is about: "Friendship."

"These guys at the end of the day always have each others' backs. In any world, that's tough to find. When you're in your thirties, you start to lose those close connections. But especially in Hollywood, it's so hard to maintain relationships when everyone's so cutthroat and competitive."

It was a long journey for him to reach the point where he could say that in front of a rapt crowd at the Banff World Television Festival during a break from writing and shooting the fifth season of the HBO show, which premieres Sept. 7. His journey, not surprisingly, involved navigating the cutthroat and competitive world of Hollywood.

It all started when his manager, Stephen Levinson, who also managed Mark Wahlberg, hoped to turn the singer and actor's life into a TV series. He brought the project to Ellin at a time when the writer/director was considering other career options. Ellin's two independent movies had tanked, he hadn't been able to get a job in Hollywood for two and a half years, and law school was starting to look appealing.

He seemed like an unlikely candidate for any project, especially a comedy series. Though a former stand-up comedian, Ellin had no television writing experience despite one of his credits. "I was not working on The Bonnie Hunt Show for about eight weeks," he explained during his Master Class session. "Bonnie does everything herself. So I sat in an office for eight weeks and nobody spoke to me."

Wahlberg's agent, Ari Emanuel, the inspiration for Jeremy Piven's Ari Gold, was pragmatic about Ellin's participation in the pilot: "If it sucks, we'll get somebody else to write it." Instead of being offended, Ellin knew he wanted the agent as his own.

Proud of the draft he turned in, Ellin was shocked to learn that HBO wasn't so thrilled. "What don't they like about it?" he asked Levinson. The answer? "They don't like anything about it."

"They had no notes, they hated it so much," Ellin continued. He decided to revise the script on his own time, "even though they begged me not to."

He even came to realize that his initial attempt had been too dark, since the story began at a point where Vince's career prospects were as dismal as Ellin's own had been. "HBO was right. It was depressing. Where was it going to go from there?" When he started from a more promising phase of Vince's life, "we got five years of ups and downs and building him up and taking it away."