A NUMBER explores the issue of human cloning through the relationships between a father and his three sons. It is also a philosophical investigation into free will and the question of whether we are genetically or environmentally determined. As it begins, a son confronts his father with the startling knowledge that he has genetically identical counterparts and is merely one of "a number." Upon this topical foundation, Churchill shifts gears to engage in a penetrating, timeless inquiry aimed at the intersection of morality, nature versus nurture, and the very substance of love.