Groom (Henry) and Bride (Alex) had been friends since childhood. Their names were taken from the children's book series, Boxcar Children, where one book is titled Treehouse Mystery. After high school, Alex ran off to the city to lead a life of freedom from the confines of their small hometown, while Henry stayed behind. She eventually realized she missed the freedom, a different kind, that only the country provided her, so she came back home and reconnected with Henry. They rekindled an old fire with each others' fun-loving spirits like they were kids again.