Join young Billy and Beatrice, squabbling siblings, as they visit imaginary neighborhoods in different time periods, and even blast off into outer space! Engaging with oddball characters like Mr. Whom (a balloon), Mr. Sour Hour (a vulture) and Mr. Darwinkle (a bearded moose), they come to grips with Big Questions, like the nature of God, time, evolution, death, and the biggest question of all: where did everything come from?