Past presidents and future

While trying to earn extra credit to pass his history class, Henry finds a trail of clues left by George Washington about an atomic bomb that was created by Benjamin Franklin. Henry also must decide whether to stay in D.C. or go back to his old life living with his parents all over the world. Meanwhile, Maggie and Jasper both run for office in the school election. The election turns out to be a tie, leaving Henry with the swing vote. In the end, Henry invites Jasper and Maggie to come with him to Mongolia over the summer. At the very end of the episode, they are seen in a Mongolian desert and hear a mysterious animal sound. This is the season and series finale, although the last thing seen on the screen are the words: "To be continued..."