The Season 1 finale finds Chris' life in disarray, so Dan uses time travel to try and get his job back, but things don't go as planned. Meanwhile, Deb tracks down Hancock and Adams with the intent of convincing them to return to the past.
Just before heading back to colonial times, John Hancock and Sam Adams meet the perfect woman, and decide that a duel would be the best way to determine who gets to court her. Meanwhile, Dan attempts to garner some good publicity for Chadwick's by setting up a meeting with a local reporter, who grills him about Deborah's identity.
The thought of losing tenure leads Chris to ask John Hancock and Samuel Adams to help reinvigorate his 2017 classroom; and Deb's dream of reopening Chadwick's ice-cream parlor come to fruition, but Dan has a few marketing ideas of his own.
Dan, Deb and Chris are stuck in 1920s Chicago, where Al Capone holds their time-travel bag hostage. Chris settles on a safe plan that uses history to take out Capone, while Dan and Deb try to befriend him instead and teach him how to be a better mobster – and husband.
Needing some cold cash for Deb to purchase an ice-cream parlor, the trio sets out to figure a way to profit from the fixed 1919 Chicago World Series, but their get-rich-quick scheme hits a snag in the form of infamous mobster Al Capone.
In need of a victory, the trio returns to the 1990s to give Dan a shot at his childhood dream: finishing a legendary "Bellybuster" ice-cream sundae at a local parlor. While Deb bonds with the parlor's owner, Chris undertakes a mission to save a life to honor his late British friend. But all plans get derailed when Dan runs into the bully who tormented him.
Deborah suspects that Dan may not be the clever inventor he claimed to be back in 1776, which leads to questions about their budding relationship. Meanwhile, Chris' mentor puts him under intense scrutiny as he works to achieve tenure at the university.
Dan and Deb travel back to colonial times to rescue Chris, and turn out to be instrumental in sparking the Revolutionary War. Later, Dan and Chris go undercover as British allies in an attempt to rally the colonists to revolt.