Ghost country / Patrick Lee.

"What Paige Campbell saw when she opened a door into seventy years from now scared the hell out of her. She and her Tangent colleagues brought their terrible discovery to the President - and were met with a hail of automatic gunfire after leaving the White House. Only Paige survived. Fearing a terrifying personal destiny revealed to him from the other side of the Breach, Travis Chase abandoned Tangent . . . and Paige Campbell. Now he must rescue her - because Paige knows tomorrow's world is desolate and dead, a ghost country scattered with the bones of billions. And Doomsday will dawn in just four short months . . . unless they can find the answers buried in the ruins to come. But once they cross the nightmare border into Ghost Country, they might never find their way back . . . "--Publisher's web site.