In the meantime, he must train to participate in the Circle of Three, a trial that would allow him to learn a double-sword-fighting technique, one he feels he needs to defend himself against the ninja's treachery. To add to his worries, his friend Akiko is acting strangely, disappearing in the night, and Jack suspects she may be training as a ninja. Bradford combines the structure of a British school story with the flavor of 17th-century Japan, and his descriptions of both swordplay and hand-to-hand martial arts reveal his extensive knowledge of the subject. Young martial artists will be eager to try out sticky-hands drills in their own dojos. Though the secondary cast is often too large to keep track of and only a few of the characters are fully developed, the ongoing struggle between honorable samurai and dastardly ninja will draw both reluctant readers and enthusiasts of Japanese history.