Holding the bottles tight you sprint upstairs. Past the zombie you destroyed. Across the hall, dodging a couple flesh eaters. Up the next flight of stairs with the dead shuffling after you. This next hall has several zombies. You run like a quarter back but you don't make it. Two leap at you and you trip and fall. You kick hard and one of them bites your foot. You are free and running towards the roof exit with many undead coming behind you now.