The fight on Zebes took Samus’ reputation from capable Space Hunter to legendary hero. Unfortunately, the schemes of the Space Pirates and Proteus Ridley didn’t end there, and the Metroids reappeared to pose a threat time and time again. Always, Samus was the one called on to put an end to them. The last time Proteus Ridley was seen, he was defeated once and for all, and the Space Pirate scourge was considered destroyed—or, at the very least, incapacitated.
Even with the Space Pirates out of commission, their large-scale attacks and constant abuse of the Metroids led the Galactic Federation to deem the Metroids too big a threat to be left alive. The decision was unanimous: the Metroids had to be eradicated. A group of researchers was sent to investigate the planet SR388, but communication was lost soon after. A search-and-rescue party of Galactic Federation Police followed, but they too went missing.
Then the Galactic Federation did what by then had become natural: they called on Samus Aran. Knowing firsthand what the Metroids were capable of and how to defeat them, Samus took the job and flew directly to SR388.
This is where our story, Metroid: Samus Returns, begins…