In 1992, Cheryl Della Pietra spent a fast-paced, drug-fueled dream of a summer working as an assistant to Hunter S. Thompson—an experience she’s spun into her equally wild first novel, Gonzo Girl.

ENTERTAINMENT WEEKLY: How did you get a job as Hunter S. Thompson’s assistant?

CHERYL DELLA PIETRA: I had a friend who was working at Rolling Stone who said Hunter had asked over there, looking for an assistant. I ended up writing this unconventional letter and faxing it. Hunter called me at three in the morning and said,

“Can you get to Colorado tomorrow?” I said, “Yes.” And that was that.

What was your first impression of Thompson?

He said, “I’m going to pick you up at the Aspen airport. I’ll be the one with the umbrella.” Like I wouldn’t recognize him!

How does your fictionalized version of Thompson differ from others, like Uncle Duke in Doonesbury?

I think the man I’ve portrayed here, Walker Reade, is a little more complex than the cartoon that was presented to the public. There was the person who would put on the Tilley hat and aviators and go out to the restaurant with the big cigarette holder, but I hope that I’ve also shown the moments where he’s more contemplative, where he’s more insecure, where he was raging—and the moments where he was a sweetheart.

Your alter ego, Alley, has an affair with a famous movie star named Larry. Can you tell us who that is?

I can’t! I will say this: Larry is a composite character.

So, a little bit Johnny Depp…a little bit John Cusack…

[Laughs] Well, the Fear and Loathing movie was ’98. I was there in ’92, so this was pre–Johnny Depp. I will say that.

What was your worst experience while you were there?

Those scenes in the book where Walker is raging and angry? Those actually happened. Dishes would fly, that sort of thing. It’s classic addict behavior. Those, I think, were the worst times.

What did you learn about yourself that summer?

I ultimately did establish the boundaries that I was comfortable with, and that made me leave. In the book, when Alley does the drug run? That’s true. That was a real turning point for me there. Like, “What am I doing?”

Were you afraid of being arrested?

I thought, “Am I a drug dealer now? What am I?” It was this moment where I was like, “Wow, I am not saying no to anything. This is not good.” I wasn’t comfortable doing all those drugs, staying up all night, subsuming my own career.

Was it depressing coming back to the real world?

A little bit. It took me a couple years to even recover from it—and I mean that more psychically than physically. Afterward, I just felt a little lost: Everything sort of paled in comparison. Hunter’s motto was “A day without fun is a day that eats s—.” That’s really how he lived his life.