Martin Widmark was born in 1961 in Sweden and today lives in Stockholm with his family. He has worked as a middle school instructor and a Swedish teacher for immigrants, but he is now a full-time children's book author. Over his career, he has also written several textbooks. He is fascinated by life's little oddities and anything unique, from food and music to languages and people. Widmark is considered a literary giant of contemporary children's fiction in Sweden. Both his Nelly Rapp and LasseMaja series are consistently on the bestseller lists and have received critical acclaim. His books have been translated into more than 20 languages.

Helena Willis was born in 1964 in Stockholm, Sweden, and now lives outside the city with her husband and two daughters. She's been working as a freelance illustrator since she graduated from Beckmans College of Design in 1991.