WHEN I met Lucy Dahl, she was still "living out of a suitcase" in her new home in Beverly Hills. She is working with the Disney corporation as a photographer and author of the James And The Giant Peach book of the film. She has already begun work on Danny DeVito's Matilda (the story of a couple of slobs who don't realise their daughter is a genius). At 30, Lucy is like a new model Patricia Neal - the same sculptured beauty, the direct, candid manner - but without the gravelly toughness.
She was frank about her experience with drugs. In a time when it is fashionable to blame one's parents for one's own adult inadequacies, Lucy is refreshingly scornful of such interpretations.
"Poor Mother and Dad were blamed people said that Dad treated us badly, that Mother was never around. But it's not true. My drug taking had nothing to do with my parents at all." There is, she says, no hidden tragedy to her pain. "I was mischievous, selfish - an adolescent. I had an extraordinary childhood, the best any child could want. I had almost everything I needed and almost everything I wanted. My parents never screamed, never shouted in front of me. I was never hit."
So what was the problem? Quite simply, Lucy had gone to work in London and, like many other girls, wanted to have a good time. "Dad coped with me when I was 17 and 18 working in London. He said, `Come home', but I did not want to, so he said, `There is always a hot meal here.'"
"But I was horrible. You are horrible on drugs. You steal from home. You steal from people. Some parents wash their hands of the problem and drive out the addict, but when I was in trouble I could always speak to him, go to Dad for advice." Dahl's problem was that, like many parents of the time, he understood about drink, but drugs baffled and probably frightened him. He set about tackling the problem in his usual thorough way.
"He went to those who knew," Lucy said. "He followed their advice. He talked to people who had been through it. When I came out [of the clinic], he listened to me, talked to me, even though I had nothing to talk about but drugs." Lucy refused to read the unauthorised biography of Dahl by Jeremy Treglown, published two years ago, which repeats - and then allows Patricia Neal to deny - the rumour that when the children were distressed, Dahl would give them the barbiturates he used against his own pain. "Someone sent me a copy of the book, but I threw it away."
So, if the problem was not family anxiety (Dahl hid his infidelity from Lucy until she was grown up), what was it? "I believe it's a chemical thing. I think you are born with this chemical dependency thing and once you start you can't stop... I get frustrated when Mum and Dad are blamed. They were great parents. I hope I will be as loyal to my children if this ever happens to me ... as it might possibly."
(For Tessa, who wrote a painful, semi autobiographical novel, Working For Love, the problems may have been even more severe. As a child, she witnessed the horrendous accident to her young brother on the streets of New York, and she alone of the family was burdened with the secret of her father's infidelity.)
To Lucy, her father's infidelity had a certain purity. "Some relationships have a natural life span, and that was the case here. But it was not a nasty affair. He fell in love. He behaved honourably by keeping it quiet until I was old enough.
"My mother was very gracious about it. Now I say, `Thank God for Liccy (Felicity)'. He loved her and she and my mother are now good friends again. Liccy kept the family together after Dad's death and brought Pat back into the fold."
What about the notion that, while he was great with little children, Dahl could never cope with adolescents? Lucy is belligerent: "Will you name me three people who are good with adolescents?"