"Dreamhouse Kings Book 4: Timescape" by Robert Liparulo

Robert Liparulo is very good at building tension in his books. And all of these books are filled with lots of suspense, action, narrow escapes, and brushes with death. While these books are aimed at younger readers (not TOO young), I don't mind telling you how much I enjoy them! (If you haven't already read my reviews of the first three books in the series, please click on the "Robert Liparulo" label at the bottom of this post).
This book, strangely enough, had more talk about God and more violence and gore than the first three. The King boys have a conversation where David gives God the credit for the new friend that they've made who seems to be exactly the kind of person they need to help them. (Xander is not so sure that God did it, however).
The boys also offer up a few vague prayers... Not directly spoken to God, but assumed to be prayers.
There is a little more blood in this book, as a character is injured fairly badly. (Can't tell you who). There is also a fascinating scene - and extremely coincidental - where David, Xander, and their father wind up on the deck of the Titanic as it is about to sink. Oddly enough, yesterday - April 15th - marked the 100th year of the Titanic disaster where over 1,500 people lost their lives. This scene and the scene of the Viking attack were particularly spectacular and brilliantly written.
Books this intense are not for all readers, but in my opinion these stories are just too good to pass up. It would not be a stretch for me to say that I enjoy this series better than I did any of Mr. Liparulo's stand-alone novels. (By the way, Robert Liparulo just released a new novel, "The 13th Tribe" - check it out and read a sample chapter at his website here. You can also read samples of all the Dreamhouse Kings books at http://www.dreamhousekings.com/)