Dio betrays Sigma, leaving Dio on 9 points and Sigma on -1. Everyone is terrified and Sigma's bracelet activates, injecting him with Soporil.
With his last remaining strength, Sigma drags himself over to Dio and demands that he hand over the Axelavir. "If he didn't, I'd die with my hands aroudn his throat." To Sigma's surprise, Dio does hand over the Axelavir, and Sigma passes it to Clover before slumping further, realising that he is about to die.
Plot Lock - "Five minutes left until death."
Sigma remembers, vagely, from somewhere, that he has cybernetic arms, and considers how this could help him. He dashes back to the number 9 door and starts to grab at Dio, trying to prevent him from leaving. Dio pulls himself out of the facility, and Sigma stretches his arm forward underneath the closing number 9 door, which crushes and severs his arm. But because it's a cybernetic arm, he doesn't die or bleed out; and since his bracelet is now attached to a disembodied arm lying on the loading dock, he can't be injected with tubocurarine. Sigma passes out from the Soporil.
When Sigma wakes up, he is in the infirmary with the others. Luna explains that she has managed to patch up his missing arm and to cure Quark. Quark appears and thanks Sigma for what he has done. Sigma decides that the facility must be a shelter for the few remaining survivors of the human race, and considers that it might not be such a bad place to stay after all - especially given the potential need to repopulate the human race, the gender ratio remaining in the base, and his only competition being K, Tenmyouji, and Quark who are all not particularly eligible.
While everyone is delighted at having managed to cure Quark, Alice bursts into the infirmary, having a similar Radical-6 fit - but now there is no Axelavir left to cure her. She begins to drive the scalpel towards her heart.
On the PS Vita version, getting this ending gives the achievement An Equal and Opposite Reaction.