Leonardo is working for the Duke of Milan in 1484, partly as a painter, but primarily as an engineer, designing machines of war.  He has devised an incredible weapon: a wood and canvas flying machine.  It’s time to build a prototype, a full-scale, working flying machine, powered and steered by a man.

Leonardo makes Dino his assistant on this project, as they have worked together before (this is the third book in the series).  Much to Dino’s surprise, his own father, a highly skilled woodworker, is hired as well, and brought in from out of town, to their mutual delight.  Just as the secret project is getting underway, though, the head apprentice, Constantin, is shot and killed by a bolt from a crossbow.  Concealed on his person are pages cut from Leonardo’s secret notebooks, bearing sketches and plans for the flying machine.  Did Constantin break faith and steal them? Or did he catch someone else in the act and get shot for his efforts?

Leonardo, wishing to keep Constantin’s involvement confidential, smuggles his body out of the castle, then pretends the young man was shot by bandits on the road - not an uncommon occurrence in those days.  Tito, another apprentice, tells Dino that he heard Constantin cry out when he was shot.  Tito sees Constantin’s body and knows this was no bandit attack.  Because Leonardo wishes to keep the secret safe, he brings Tito into his confidence, and Tito is put to work helping with the project.

The plot gets ever more complex, and when Leonardo, the flying machine, and Dino’s father all disappear, Dino, who is after all still very young, must find a way to bring them to safety.  This she does with the help of an unlikely ally, despite treachery and many complications, as the book winds ever more craftily to its exciting conclusion.

A Bolt from the Blue is an engaging story, well told.  I thoroughly enjoyed it.  The real Leonardo da Vinci did invent a flying machine, and the drama in this tale could plausibly have happened.  Though Leonardo is vital to the story, his appearances are fairly brief.  The writer is wise to use such a famous character sparingly.  Granted, it is hard to believe that a young woman could live in a dormitory, even one with sleeping alcoves, with many young men and still maintain the secret of her gender month after month.  Aside from that, and one over-written, bright-lights-and-benevolence near-death scene, I have no quarrels with the book.  No, I take that back: I wish my favorite character, a charming dog named Pio, had played a larger part in the story.  I look forward to reading other books by this writer; perhaps Pio will figure more prominently in them.

--Nancy McIntyre