Divide and Conquer by Carrie Ryan - Infinity Ring 2

Dak, Sera, and Riq land in France, while it is under attack by Vikings, talk about getting your blood pumping! 
As you read more information is given about the SQ, Time Wardens, and Historyans and Riq begins to give some insight into his character
Another fast paced, fun read.

A Mutiny in Time by James Dashner - Infinity Ring #1

Time travel is always interesting and has been done many times but what makes this interesting is the major events of history that are different.  Of course you have to have three very different yet brilliant youth to save the world, that is a rule of YA fiction. 
A fun, light, read that makes you stop and review your history on more than one occasion.  This is the first in a multi-book series that will appeal to many readers.  The authors vary and there is a game to play so it should be a series that hooks a lot of people.