A superb series of graded readers using the highly acclaimed phonic approach developed by reading expert Ruth Miskin. There are four levels - Blue (the easiest), Green, Purple and Turquoise (the hardest). Each level is linked to one of the core Superphonics books. Purple Storybooks practise the sounds taught in Superphonics Book 4. All the Storybooks are fun to read and beautifully designed and illustrated in colour. White Knight focuses on the following sounds: 'igh' as in 'fight' and 'i-e' as in 'white'.