Seven One Three Nine (7139) or just Seven as it refers to itself as, is a sentient machine is a one hundred eighty-two year old, steam powered machine. Originally designed as a service and security automaton, it has laid dormant for over one hundred fifty years.

Its body is solid brass, a boiler attached to its back and, from what's exposed by the damage in its chest, its insides consist of a mass of gears. Its limbs can extend multiple times their length. It seems completely self aware with strong moral ideals of right and wrong.