LOS ANGELES — Dominic Monaghan plays heroin-addicted rock star Charlie on ABC's hit series "Lost." Cozied up on the back patio of a Melrose coffee house, the actor revealed his own rock-star side.

While on leave from the O'ahu set, Monaghan, 29, came to talk about Wednesday's hallucination-filled episode, which flashed back to Charlie's past and hurled him into an uncertain future. But he also talked about love (with co- star Evangeline Lilly), drugs (Charlie's habits and his own) and rock 'n' roll (well, mostly John Lennon).

His interest in the late Beatle goes deeper than the typical fan's. Many nights, he dreams of Lennon as his "God figure," and most days he surfs in the ocean, which he considers his personal "Strawberry Fields," "a place of tranquility where I go to forget everything." His fascination with Lennon started on his fourth birthday, the day Lennon was murdered. Tattooed on his arm is the Lennon lyric: "Living is easy with eyes closed."

Monaghan believes he has found his Yoko Ono in Lilly, 26 (Kate on the show). "My ultimate search has been for a muse," he said of his girlfriend of more than a year. Someone "you can bounce ideas off and share artistic dreams with. It feels like I'm on the right track."

It's Lennon's example that inspires him to talk about drugs. While most celebrities cover up or downplay any risky behavior, Monaghan speaks freely about his past experimentation with marijuana and hallucinogens. He does so, he said, because that is what Lennon did.

"I came to understand that The Beatles grew a lot and understood a lot about themselves through taking certain drugs," said Monaghan as he waved away a spider weaving its way down into his teacup. "There's something very rewarding and sobering about getting involved with certain hallucinogens that strip away any sense of ego."

That contradicts his character's drug use, he said. Monaghan has long viewed Charlie's drug of choice, heroin, as "the ultimate No. 1 nightmare" and has steered clear. "You don't hear many happy heroin stories. And I'm not into the idea of sharing needles."

'AN EDUCATION'

Monaghan, the German-born son of a science-teacher father and nurse mother, first tried drugs at age 15 or 16, "when I was growing and finding a sense of who I was." But he stresses that he has never been an addict like Charlie. And, "I don't condone the use of drugs."

"Abusing drugs," he said, "is a mistake. But I've never felt that I've abused drugs. I've always used them. For me, it's always been an education, and I've always had a pen and paper with me whenever I've been involved in any kind of drugs. A door in your mind opens, and you may as well write down what you're experiencing in that state. I think I have the ability to use it as a tool. Some people don't."

Monaghan's research for the role of Charlie led him to conversations with actors who have fallen victim to heroin and other drugs. And he has known people who have overdosed or gone into rehab. "You see human beings at their lowest ebb when they would slit your throat for another bag of cocaine or a rock of crack."

The "Lost" writers concocted quite the dilemma for Monaghan's Charlie in the last episode: a Catholic character faced with having to break statues of the Virgin Mary to get to a drug that could end his life. "That all has to do with the big thematic master plan of the show," hinted executive producer Bryan Burk.

But the producer believes parents — not the TV show — have the responsibility to teach kids about the dangers of drugs. "We just present the best and most realistic entertainment that we can," Burk said. "We're not consciously trying to do pro- or anti-drug programming." But he also emphasized that "there is no happy ending to a heroin addiction ... ever."

Urged on by visions, Charlie set a fire and tried to run off with Claire's baby. His actions caused his fellow plane-crash survivors, particularly Claire (Emilie de Ravin), to look at him in a different light. "He's definitely becoming an outcast," de Ravin says. "So Locke (Terry O'Quinn) is stepping in to take care of Claire."

And that does not sit well with Charlie, whose odd behavior, according to Burk, will "dramatically alter the way all the islanders relate to him for the rest of the season."

Monaghan said that, unlike Charlie, he is in a good place.

His "Lost" success comes after his blockbuster turn in the "Lord of the Rings" films, where he gained a sizable, and loyal, fan base.

He has been alcohol-free for more than a year. (Swearing off booze was his 2005 New Year's resolution.) The change, he says, has left him feeling "more present, clear and aware."

And he met Lilly.

For the most part, the couple refuse to modify their lives to avoid celebrity photographers, who often track them. They might drive around and around in a loop near his Hawai'i home to bore shooters into leaving them alone.

But one incident did have him fuming. The couple were vacationing in Joshua Tree National Park in Southern California, and, "This guy — this thing — had been following us for at least two hours into a very private place. We were having a nice weekend, and then shots appeared of us in the house we were staying at, through the window. Us making breakfast and stuff. Shots of us sunning on rocks. Going into town for Mexican food."

CREATURE CONNECTION

Though often inseparable (they hang out in each other's trailers between scenes), Monaghan and Lilly have separate homes on O'ahu. She lives with two girlfriends, while he bunks with pet chameleons Karma and Traffic Light.

He also has played parent to cockroaches, lizards, scorpions, a leaf mantis, a black widow spider and an albino snake. "He's always collecting bugs for them on the set," said de Ravin, with a laugh. "He'll drop them in old nut containers. His pets are lucky to have him."

As Monaghan tossed granola pieces to an appreciative squirrel, he flashed forward to the day when he could transfer his caregiving skills to human babies — perhaps as soon as "Lost" concludes its run.

A STAY-AT-HOME DAD?

Asked when the timing will be right, he once again referenced Lennon, who was "financially, spiritually and emotionally" prepared to be a stay-at-home dad with son Sean.

"We'll see where I'm at at the end of 'Lost,'" said Monaghan, an admirer of the familial path taken by Angelina Jolie and Brad Pitt. "Maybe one or two children of my own, and then what I really hope to do is adopt — perhaps a bunch of them."

Monaghan said he is now experiencing the highest highs of life, playing a role he treasures and falling deeper in love with Lilly, without any need for artificial enhancement.

"The temporary highs that I've felt on drugs pale in significance to the highs of a sober mind, catching a good wave in the water or being in love, or hugging my mama or feeding my chameleons."