After defeating the four main bosses ( Kraid
) Samus returns to the golden statue room in Crateria
. The jeweled eye in each of the bosses statues breaks and the statues crumble to the ground revealing an elevator into the space pirates' headquarters, Tourian. While traveling through Tourian, Samus reaches an area where the Metroid Hatchling
(now fully grown) comes out of nowhere and attacks an enemy. After killing the enemy it proceeds to attack Samus draining all of here energy tanks and leaving her with just one blip of energy.
After recovering at a nearby energy machine, Samus eventually confronts Mother Brain
who resides in her signature glass tube. Once Samus does enough damage to Mother Brain the tube collapses and Mother Brain reveals her true form. Halfway through the battle Mother Brain begins to drain all of Samus' energy using a beam attack. Before Mother Brain can unleash the killing blow the Metroid Hatchling appears and attacks her. While Mother Brain is stunned from the attacked the Hatchling begins to regenerates Samus' energy. However, Mother Brain recovers from her stunned state and begins to attack the Hatchling while it is in the process of helping Samus. Mother Brain deals a final blow to the Hatchling killing it, but right before it dies it uses the last bit of its strength to give Samus the power of the Phazon Beam which Samus uses to easily finish off Mother Brain.
After Mother Brain is defeated a self-destruct sequence
is activated and Samus has 3 minutes to get out of Tourian and escape planet Zebes
before it explodes.