Samus responds to a distress signal from Ceres Space Colony, where the baby Metroid was being kept for research.

Explore the Station

After the elevator stops, go to the bottom of the room and go through the door on the right. Go through the next room, then go down the stairs to the bottom of the next room and go through the door. Continue going to the right to reach the next room.

Go through the next hallway and approach the baby Metroid. After a few moments, Ridley appears and takes the baby Metroid. This battle will either end if you shoot Ridley enough times or if you let Ridley bring your HP below 30. It is faster to let him damage you until the battle ends. Stay near the right wall to get hit repeatedly by Ridley's tail to make the battle end sooner.

Escape the Station

After Ridley flies away, the colony's self-destruct sequence is activated. You have one minute to escape. Jets of steam and falling debris will slow your progress, but won't damage you. The tall room that leads up to the elevator will rock from side to side as you go up. At the top, jump onto the elevator and you will automatically escape.

After the Ceres space colony self destructs, you arrive on Zebes.