1864: As war ravages the nation, on the outskirts of the Civil War, it is business as usual for slave-owners and traders. Will is a fatherless thirteen-year-old boy who survives by working with a white bounty hunter gang. They send him to earn the trust of runaway slaves in order to lure them back to the south. On a dangerous mission into the free north to find Nate, a fugitive freedman, things go wrong, and Will and Nate find themselves on the run....

Underground tells the story of American heroes and their harrowing journey from slavery to freedom, with the legendary Harriot Tubman blazing the trail.

Eager to flee from his drunken father and the confining life with Widow Douglass and Miss Watson, Huck sets off on a raft down the Mississippi with Jim, a runaway slave, in tow.