When Earth, a dying planet, is destroyed by the effects of climate change, a four-year-old Lena finds herself strapped inside a pod and sent away from her world, and towards a planet her father found circling a red sun. Upon her arrival, ten years after her pod had been launched, she finds herself on Krypton, a planet that isn't kind to her human body. The weight of a red sun is too much for her fragile physiology to bear, and with the threat of a shortened lifespan, Lena spends her days in isolation trying to find a cure for herself, instead, finding superhuman powers along the way. With the powerful House of El turning against the people of Kandor City, Krypton finds itself needing a hero, but with her frail body in danger, Lena has to choose what matters most to her; her health, or protecting the people she cares about.