[quote=supertinyking]
Blood touches it, and tries to sense what it is.
[/quote]

He finds something... off. No real explanation, no nothing, he just knows it's bad news. It's a case of pointing out 'the sky is blue'. Zero is being assaulted mentally, and soon he begins writhing again, which leads Madison to successfully restrain him this time, and the assault becomes physical, from no proper source. He gets glimpses of the horror Zero is experiencing, watching his friends and family die, being tortured himself, but there's so much more realism than a dream. Whatever this is, it's crafted Zero's own personal little Hell inside his head.