I didn't know what to think when I found it either. Don't you just love the charred 12 AWG neutral and the gound wraped around the NM. Oh and the 30 amp breaker
I wouldn't be a bit surprised if the wires were connected to the wrong terminals on that plug also. Looks like a complete failure from one end to the other.
This "creation" was just hanging out of an FPE panel, hooked up, with no cover in place? Hmmm, I wonder what was holding the rest of the breakers in place...?