In Metroid: Zero Mission, a remake of the original Metroid that replaces it in continuity, Samus is ambushed by Space Pirates while escaping the planet after killing Mother Brain, and her Starship crash-lands back on the surface. She confronts the cybernetic lifeform Mother Brain, as well as its guardians, Kraid and Ridley. Samus travels through the caverns of planet Zebes to stop Space Pirates from exploiting the Metroid species for galactic domination. Timeline of the Metroid series Metroid/ Metroid: Zero Mission 1.7 Metroid II: Return of Samus/ Metroid: Samus Returns.