I picked Tony O’Neill up at a taco shop on Sunset Boulevard and we headed east. One thing you need to know about the Sunset Strip is it is always changing. Hotels, restaurants, billboards. There are no sacred cows in Hollywood, but the strip is the least sentimental spot in Los Angeles.

Driving east on Sunset is like going backwards in a time machine after a bad trip into the future. All you can do is look back and cringe, which is something Tony O’Neill excels at. His latest novel, Sick City, is a depraved romp through the dark side of Hollywood, told by someone on intimate terms with its underbelly.

RULAND: What brought you to Los Angeles?

O’NEILL: I was playing with a band in England called Kenickie, like from Grease. We were on the fringes of the Brit Pop thing in the mid-‘90s. We were an all-girl band apart from me and the drummer. We had a couple of hit singles in England in the mid-‘90s, and then we did our first U.S. tour.

RULAND: What’s your first memory of L.A.?

O’NEILL: A big decadent party in one of Howard Hughes’s old houses in Brentwood. This girl was house-sitting the place apparently, and it had been going on for two days. Nobody else in the band really did drugs the way I did. I was up for anything. So we got invited there, and someone offered me some speed. I’d done speed in England, which is a different proposition from meth.

RULAND: Just a little bit.

O’NEILL: (Laughs) Speed in England is like taking Sudafed. It’s really not very strong. It was what you would do if you couldn’t get a real drug. So I did a big old line of this stuff, thinking it was the same. No exaggeration, three days later I still hadn’t slept, and I was in Vegas and I’d married a chick I’d met at the party. That was it. I finished the tour, quit the band, and moved to L.A. to live with this girl. It didn’t work out, funnily enough.

RULAND: Fancy that.

O’NEILL:  All that is in the first book, Digging the Vein. And that’s how I fell into using heroin. After that marriage broke up, I was kind of adrift in L.A. with not a lot to do.

RULAND: How long did you live in L.A.?

O’NEILL: I moved out in 2000. It was a good solid four or five years. You know, when I left L.A. I had to leave. I decided to go to London because I knew I could get on a methadone program there.

RULAND: When you say you had to leave, what does that mean?

O’NEILL: I was incredibly strung out. I’d been in rehab a couple of times. I couldn’t get clean. There was something about being in L.A. and having all of my drug connections, I could never stay clean here, you know? The temptation was too much. In London I’d never used hard drugs.

RULAND: Such as?