The Cellar: A Novel by Minette Walters Penguin/Random House, $24.00, 246 pages, ISBN 978-0-09-959464-2 One of the great things about reading is when you figure out that it’s a voyage of personal discovery . . . and the more you read, the longer your journey into the unknown, which in turn takes you to places you couldn’t imagine before opening that book you’ve just read . . . and