Just because you graduate doesn't mean the adventures are over...

It's a semester break from college, and the graduates of Mr. Greene's time-traveling history class are home for vacation. However, where other freshmen may find themselves at the beach or parties, Mr. Greene convinces his alumni to make one more trip and help his current senior class learn the origins of the anti-slavery movement in the United States.

With Nikola Tesla once again at the controls, Mr. Greene and his troop of students, past and present, soon find themselves caught up in the abolition movement. Samuel attempts to assist Harriet Tubman with a rescue mission in Maryland while the others cross paths with the likes of Harriet Beecher Stowe, Frederik Douglass and William Lloyd Garrison. Not to mention one extremely familiar young man destined for stovepipe hats...and the presidency.

Abolitionists, slavery and a country turned upside down. Can the students make it home safely without altering history, or is this one last trip a step too far?