The first one that I want to mention is the Young James Bond series. Number one in this series by Charlie Higson is called SilverFin. This series starts when James Bond is thirteen years old. A young man full of ambition and looking for excitement, what could be better than a mystery, and what could be better than becoming a spy.
Another series that will appeal to those who enjoy mysteries and historical fiction is The Agency: A Spy in the House by Y.S. Lee. Miss Scrimshaw's Academy for Girls is a very special school. It provides a fine education, training in manners, and a very unique job upon graduation. The graduates find themselves employed by the rich to be companions. Little do their employers know that they are there to spy on the house.
The final series that I will mention today is Palace of Spies by Sarah Zettel. When our protagonist is thrown out of the house for refusing an arranged marriage, she finds herself thrust into the life of a lady in waiting to royalty. Her arrival at court came with instructions to spy and she builds the trust of the family as she puts her own life in danger.
So, if you like mystery and danger, maybe you want to try a spy story.