Exactly, it was their hope versus the hope of the traitor! But it would have been fine. If we all died, we deserved it. And the traitor, who was completely innocent would live!

If they were able to reveal the traitor, than their hope would have been greater, and the rest of the class would carry on. That would mean that perhaps there was a reason for them to continue and there was a chance for redemption.

[Because... his luck....]

I was told in the end, Nanami san, who was the traitor revealed herself.

[Though he hadn't explained how he set it up so it was the traitor versus the rest of them.]