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ost_uid0]Opium[/b

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I believe you're thinking of A Swiftly Tilting Planet, by Madeline L'Engle (spelling is suspect). I think she wrote A Wrinkle In Time as well. I have no idea what she's written for adults, but I seem to recall some inane pre-teen girly book about hair-washing that I got halfway through before I realised it wasn't SF.[/color

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