Book excerpt: It's time to welcome new girls to Malory Towers, the famous boarding school by the sea, in four brand-new stories by outstanding authors, set in Enid Blyton's much-loved school. YA and Waterstones Book Prize-winner Patrice Lawrence introduces us to proud Marietta with her magnificent head of braided hair. A dormitory argument reveals something unusual about Marietta, and something equally unexpected about Alicia. In Guardian and Stylist columnist Lucy Mangan's story, student librarian Evelyn is wary of her lively, lacrosse-playing classmates. When one of them becomes a regular visitor to the hushed domain of the library, can Evelyn really trust her? Sunita Sharma joins Malory Towers surrounded by a sense of mystery, in Narinder Dhami's fabulous story. But is Sunita really as glamorous as Gwendoline imagines? In Rebecca Westcott's heartwarming story, Darrell and friends fear the worst when spoilt Gwendoline's cousin joins the school. But Maggie is very different from her stuck-up relative . . .