Katniss volunteers because, well, perfect opportunity to teach the mages a little stealth. She doesn't want to get caught and she most certainly does not want to die because they do not know how to get around without keeping silent.

She's not pleased that Korrin brought her staff, and she kneels near her as she peers out into the darkness, counting the guards. Then she looks at the stone outcroppings, and nods.

"Up there. Best vantage point. We can see down into each area of the mines." She gives Korrin a stern look, "Remember, the deaths have to look like accidents."