Based on the Geoff Johns/Gary Frank 2008 release Superman: Brainiac, Superman: Unbound finds the horrific force responsible for the destruction of Krypton – Brainiac – descending upon Earth. Brainiac has crossed the universe, collecting cities from interesting planets – Kandor, included – and now the all-knowing, ever-evolving android has his sights fixed on Metropolis. Superman must summon all of his physical and intellectual resources to protect his city, the love of his life, and his newly-arrived cousin, Supergirl.