Although the protagonist in Nick of Time by Ted Bell is only twelve years old, the book isn't appropriate for most young readers because of the violence and gore. I'm not fond of those factors either, but in this book they're essential to the plot and setting and not gratuitous.
The book is also longer than most Middle Grade novels.
So, what kind of book is this? That's hard to say. It's an adventure, it's a fantasy, and it is historical fiction happening in two different periods of time. Nick and some other characters move back and forth between 1939 and 1805 but all the events occur in the English Channel while England is threatened by enemies they are not fully aware of.
The book carried me back and forth between both of those realistic and believable times.
The characters seemed alive, too. (I especially liked Nick's smart but naive little sister.) Kids who read Nick of Time will love the courageous choices they make. Anyone who likes to experience fictional worlds of scary adventure will enjoy this book.