Ask the woman what happened.
From Create Your Own Story
"Did you know that man?" You ask. She nods.
"He was my boyfriend." She mutters, watching you as you tend to her wounds.
"Does he always show his affection by attacking you with a knife?"
"Har har," she says, giving you a smirk. "No. He's been acting weird all night. Then, out of nowhere, he picked up a knife and came at me."
"Any idea why?" You ask.
"He started getting more violent as he started to get sick," the woman says quietly, then winces when you wipe away some blood from the cuts. "He was attacked on the subway this afternoon. Got into a fight. Got a nasty scrape and was bit pretty deep. Within hours, he started getting a fever and the wounds looked infected. Then he started getting blisters on his face. We were going to go to the hospital, but then this storm came out of nowhere."
So, like a zombie? Is that what this is.
