Sibéal Pounder is the author of the bestselling Witch Wars and Bad Mermaids series, as well as the World Book Day mash-up, Bad Mermaids meet the Witches. Before becoming a full time author, Sibéal worked as a writer and researcher for the Financial Times, with other writing credits including Vogue and Glamour online magazines. Beyond Platform 13, the sequel to Eva Ibbotson's classic The Secret of Platform 13, is Sibéal's first standalone novel.
Beatriz Castro's books have been published all over the world, her illustrations appearing in textbooks, picture books and on covers.
She is also the illustrator of Jessica Townsend's bestselling and Waterstones Prize-winning Nevermoor. Beatriz lives in Spain.