About the book: year / Alfred Hitchcock is a famous American film director, famous for his detective films. And the three detectives are his young friends Bob Andrews, Pete Crenshaw and Jupiter Jones. They live in a town near Hollywood. Their stronghold is a salvage warehouse, their headquarters is an old caravan in which they have equipped a crime laboratory. Their agency "Three Detectives" reveals any secrets, riddles and puzzles. Friends-detectives boldly take on the most important and complicated cases and bring them to the end with honor. The boys follow the trail of a gang of robbers who use a mask with a terrible scar.