A gripping middle-grade mystery from internationally best-selling author Astrid Lindgren. For most the summer holidays in a small Swedish town would be spent swimming, fishing, or sailing. But a super sleuth like Kalle Blomkvist is always looking for the next case to crack. So when a mysterious stranger arrives in town he finds the perfect excuse to start an investigation, one that will draw him and his friends into a thrilling case of theft and deception. The first of three thrilling detective stories for readers of 9+, perfect for fans of character led mystery book such as Murder Most Unladylike and Ruby Redfort.