 Intergalatic bounty hunter Samus Aran has been hired by the Galactic Federation to solve the mystery of what happened to a group of Federation Marines, all of whom vanished on the planet Aether. When Samus arrives, she finds every one of the Marines dead, apparently attacked by shadowy creatures that caused extreme fear-but in the middle of her investigation, she sees a figure that looks surprisingly like...herself, in a dark-colored suit. Samus follows her double into a portal that leads to a world filled with the same shadowy creatures that the Marines  logs hinted at! Samus eventually learns of the evil that surrounds the planet Aether. It would appear that a meteor carrying Phazon, the mutagen-compound that the Space Pirates were using on Tallon IV, struck the planet, creating a "Dark Aether" where an evil race known as the Ing appeared. The Luminoth, wise creatures that lived on Light Aether, warred with the creatures, but they are being destroyed due to the Ing s theft of their own planetary energies. The Luminoth beg Samus for her help in restoring the energy and destroying the darkness forever. Samus agrees...and a new adventure begins!