Patrick Ness is the author of the critically-acclaimed and bestselling Chaos Walking trilogy. He has won numerous awards including the Guardian Children's Fiction Prize, the Booktrust Teenage Prize, the Costa Children's Book Award and the Carnegie Medal. He lives in Los Angeles, USA. Siobhan Dowd was the widely-loved, prize-winning author of four books, two of which were published after her death from cancer, aged 47. In 2009, she became the first author ever posthumously awarded the Carnegie Medal.

Jim Kay studied illustration and worked in the archives of the Tate Gallery and the Royal Botanic Gardens, Kew, two experiences that heavily influence his work. His images for A Monster Calls use everything from beetles to bread boards to create interesting marks and textures. He lives in Kettering, Northamptonshire.