Near the end of the game, the party attempts to cross a desert. After weeks, they're forced into battle with a powerful monster that pushes them beyond their limits. Nina falls prey to exhaustion as a result, leaving her on death's door. Ryu is left with a choice; save Nina by slaughtering their guide animal and using it's meat to restore her to health or sacrifice her and potentially risk everyone by pressing on.

Because without the guide animal, they can't find their way back.