Frenzy by Robert Liparulo

Their destiny is to fix history. Their dream is to get home.

When you live in a house that's really a gateway between past and present, you have to be ready for anything. It's a painful fact the Kings have faced since moving to Pinedale eight days ago. Desperately trying to rescue their mother from an unknown time and place, brothers Xander and David have lunged headlong into the chaos of history's greatest--and most volatile--events. But their goal has continually escaped their grasp.

And worse: Finding Mom is only a small part of what they must do, thanks to the barbaric Taksidian. His ruthless quest to sieze their house and its power from them has put not only the family, but all of mankind, in grave danger.

Somehow, the key to it all hinges on Uncle Jesse's words to the boys: "Fixing time is what our family was made to do." But how can they fix a world that has been turned updisde down--much less ever find their way home?

At long last, the secrets of the house and the King family are revealed in the stunning conclusion to this epic series.