Alastair Chisholm began his career as a software developer in Edinburgh. His interest in devising and tackling logical problems led him to create the hugely successful Kids Book of Sudoku and Kids Book of Karuko puzzle book series. He is the author of the highly-acclaimed sci-fi adventure Orion Lost (Nosy Crow) and picture books The Prince and the Witch and the Thief and the Bears and its companion title, The Tale of the Valiant Ninja Frog, both illustrated by Jez Tuya. Alastair lives in Edinburgh. Find him online at [...], on Instagram as [...] and on Twitter [...]

David Roberts is the author-illustrator of the Dirty Bertie books and the illustrator of many books for children, including the bestselling Rosie Revere, Engineer and Ada Twist, Scientist, written by Andrea Beaty, several titles by Julia Donaldson, the Kate Greenaway-shortlisted The Dunderheads, written by Paul Fleischman, non-fiction children's book Suffragette: The Battle for Equality, and the picture books The Dumpster Diver, written by Janet S. Wong, and His Royal Tinyness, written by Sally Lloyd-Jones. Born in Liverpool, he now lives in London. Find him online at [...].