Brashares, Ann. Westfallen (Series) #2

"Former best friends Henry, Frances, and Lukas thought they'd managed to restore history to its original path after their antics with a time-bending radio went awry. But they're still trapped in Westfallen, the version of present-day America where the Axis won WWII, living an alternate--and much darker--version of their lives. Henry has to work at the Home for Incurables, Lukas is on hard labor all day, and only Frances, whose parents are members of the Nazi elite, gets to go to school and move freely. And since they and their friends in 1944 destroyed the radio, they have to find cruder and ever-more-desperate ways to communicate across time. Frances uses her privilege in Westfallen to gather as much information as she can, while Henry tries to turn Lukas into a local baseball hero to save him from being sent away to a work camp. But the deeper the three friends and their 1944 counterparts dig into how Westfallen came to be, the more they begin to attract unwanted attention from people with a vested interest in making sure this version of history becomes permanent...at any cost."--