fourth World Paperback -

His Past Is Her FutureLife On Mars Isn,t All It,s Cracked Up To Be When You,re Isaak ContrerasEver Since His Dad Disappeared Two Years Ago, Isaak,s Been Struggling To Keep Up In School, And He Never Seems To Be Able To Live Up To His Mom,s High ExpectationsBut Everything Changes When He Finds An Ancient Coin Among His Missing Father,s PossessionsThe Coin Makes Him ATarget Of Both The Martian Colonial Government And ACrazed Scientist With AVendettaand It Leads Him To AGirl From Another Time Named Nadin, Who Believes That Isaak Might Just Hold The Key To Saving Both Their WorldsThat Is, If They Can Survive Long Enough To Use It..'