Classics, modern fiction, non-fiction and more. Written for secondary and adult students the Oxford Bookworms Library has seven reading levels from A1-C1 of the CEFR.Another grey London day. At 221B Baker Street, Sherlock Holmes is bored and gloomy. So when Miss Morstan requests Holmes's help to find her father and explain the mysterious pearls being sent to her, Holmes and Watson welcome the new adventure. Holmes's mood lifts as he reveals a complicated story of lost Indian treasure and murder.CEFR: B2/C1Word count: 30,635.