With carefully adapted text , new illustrations , language practise activities and additional online resources , the Penguin Readers series introduces language learners to bestselling authors and compelling content . Titles include popular classics , exciting contemporary fiction , and thought-provoking non-fiction . Sherlock Holmes - The Hound of the Baskervilles, a Level 3 Reader, is A2 in the CEFR framework. The text is made up of sentences with up to three clauses, introducing first conditional, past continuous and present perfect simple for general experience. It is well supported by illustrations, which appear on most pages. After Sir Charles Baskerville dies on the moor near his house, his friend Doctor Mortimer visits Sherlock Holmes in London. \"Sir Charles' pipe was on the ground near the gate, and between Sir Charles and the gate, I saw footprints,\" Doctor Mortimer tells the famous detective. \"They were the footprints of an enormous hound!\".