you and natsumi were trying to find survivors so you can bring them in the future foundation shelter, you and natsumi constantly fought the infected, the smell of their blood and rotting flesh polluted the air, you are immune so that's the next best thing, you were walking in the forest trying to find the future foundation shelter. While natsumi noticed a blood trail.

Natsumi: "damn... there's a trail, damn thing probably mauled somebody, I'll have to deal with it, like usual." she said, rolling her eyes as she follows the trail, she looked up, she saw ibuki, she was frozen as she stared at the infected corpse of the ultimate imposter. Natsumi: "it looks like she's starin' at his corpse... ibuki...?" ibuki didn't pay attention, she just crouched down to the ultimate imposter's level, about to touch the blood. Natsumi: "shit! Ibuki! No!" natsumi ran up to ibuki and lunged at her before she got in contact with the infected blood. Natsumi: "you should've moved!! You could've gotten infected!"