It was a dark night on planet XN294. A pitch black cave, exposed by the light of the planet's moons, writhed with life. Evil, parasitic life. Metroids. Hundreds of them, Infants to Omegas, crawled, floated and stirred in the deep cavern. They were waiting for the call to action. The call to feed. Some distance away from this cave, Nitox the Zoomer and his friend Samus Aran followed traces of Metroid DNA. Zoomers have extremely acute senses, as well as advanced tracking devices, so Nitox and Samus had no problem finding the cave of Metroids. Countless battle strategies were thought up, only to be scrapped. It was nearly impossible to take on so many Metroids at one time. Samus knew that the Metroids were only weak to Ice-based weaponry, and Nitox knew that one arm cannon wouldn't be enough. If only there were a way to temporarily freeze the Metroids, that way the two could at least get a head start. Then, and epiphany hit the little zoomer. Combining the freezing capabilities of the Ice Beam with the spreading effect of Power Bombs, Nitox created the ultimate anti-Metroid weapon: the Sub-zero Implosion Grenade, or SIG. Using this unique combination of Samus' upgrades, the duo might be able to freeze the Metroids long enough to kill a sufficient amount, then escape the cave to hide again. The process would be repeated until the Metroids were obliterated.