RACHEL"S HOLIDAY, Marian"s classic novel about addiction, is being given a new lease of life with a fantastic new jacket treatment. Here"s Rachel Walsh, twenty-seven and the miserable owner of size 8 feet. She has regular congress with Luke Costello, a man who wears his leather trousers tight. And she"s fond - some might say too fond - of recreational drugs. Until she finds herself being frogmarched to the Cloisters - Dublin"s answer to the Betty Ford Clinic. She"s outraged. Surely she"s not thin enough to be an addict? Heartsick and Luke-sick, she seeks redemption in the shape of Chris, a Man with a Past. A man who might be more trouble than he"s worth.