[She pauses to nibble on a bit more popcorn before taking a deep breath:]
Okay, from what I think...the trainwreck had actually carried some sort of biological weapon thing that the girl is immune to because why not? The chainsaw guy thinks the detective has been infected, but judging by the so-not-subtle makeup, he really has.
There may or may not be a love triangle in here somewhere. I can't even tell.