Did people have handguns in 1453? Would a teenage monk know what one sounded like? 
 Unfortunately, I was put off by the very first sentence of this book: 
 "The hammering on the door shot him into wakefulness like a hand-gun going off in his face." 
 I'm not convinced. Is this just bad imagery or is it awful research? 
 Perhaps if someone can show me historical records showing that a 17 year old monk could know what a hand-gun sounded like, then I will read. A hand-gun mind, not one of the musket-style guns I know they would have access to in those times.