In the third book of the series, Andy unveils a scientific breakthrough that will make time travel practical. He and Mark, and new friend Amy, test the enhanced program and discover that something has gone wrong! The trio becomes separated in the past and returning home seems impossible. But the friends are determined to reunite, and the only way to accomplish their goal is to travel the roads that lead to the one place that they desperately wanted to avoid - the banks of the Little Bighorn River. Along the way the time travelers meet Sioux leaders Sitting Bull and Crazy Horse, ride with General George Armstrong Custer and the U.S. Seventh Cavalry, and become part of the history of Custer's Last Stand!