Now Inglethorp's out of the way, there's no one else; no one, I mean, except ”one of us." Yes, indeed, that was nightmare enough for any man! 
The murderer had to be someone from the outside. 
mnli hypothesis: The murderer had to be someone from the outside.  premise: Now Inglethorp's out of the way, there's no one else; no one, I mean, except ”one of us." Yes, indeed, that was nightmare enough for any man! 