After Samus wiped out the lethal X parasites along with planet SR388, the Galactic Federation receives a video transmission from an unknown source indicating that the X are still alive. They dispatch a special unit of seven EMMI robots (Extraplanetary Multiform Mobile Identifier) to ZDR, the source of the transmission. Soon, the unit vanishes and Samus travels to ZDR to investigate. She is in conflict with Raven Beak, the Mawkin leader who plans to use the Metroids as his ultimate weapon for conquest.
