Pete was deep in enemy territory; he was fine with that. Better to stay on high alert and need it than be able to relax and get killed. He woke as the sun was setting, and began readying his weapons for the coming night. He still had enough food to last, so he wouldn't be hunting for anything more than a body count. He'd broken triple-digits last month, counting from when the infected had begun fighting. He didn't know how many there were in New York, nor how many this building held...but he knew he was a meal; that was the interesting thing about their situation. They preyed on each otehr, but so far the beasties hadn't won a single hit on him. He'd been careful.
Pete kept reminding himself of these things as he prepared to go out and face the fully infected once again, made sure all his armor was in place, made sure his guns were clean and well-oiled, his knives good and sharp.
Finally, full night fell and he began to hear noises outside his door. He walked into the main floor of the executive office he'd remade into a safe room. During the day, the full window would begin cooking anything that managed to get through his door. At night...well, he wasn't there at night unless things went bad. Then, a metal door was secured by four bars held in place by an iron rod that could only be removed by using the combination lock. That way, if he somehow slipped into the sickness the rest of them had succumbed to, he'd never be able to get himself out to hurt anyone. He'd starve to death instead.
Quiet from beyond the 'front door.' He popped it open just a hair, 'pie'd the doorway until he was satisfied, then slipped out and secured the door behind him. Moving quietly on the marble floor, he caught a small grouping, five of them, clustered together on a stairwell. The mechanics of the MP5-N clacked away, louder than the whuffing of the silenced rounds as they splattered into the brains of their targets. One of them was still moving though, and he had no time to waste. Vaulting the bannister and aiming for the rising creature, he drove it to the ground with his knees, letting it break his fall. Then he reached down and snapped its neck, severing the spinal cord. Satisfied only when the body relaxed, Pete finally stood and eyed the next landing of the stairs. Nothing; but there were sounds from below. He thought a moment. going back up the stairs to the only other approach they would have on the stairs, he set a trip-wire connected to a smoke canister. Useless for anything more than a warning, but it would give him what he needed. Then he began a slow, careful descent down the emergency staircase. He had all night for these things.