Many elements of the film It Comes At Night (2017) were intentionally left vague, but I'm left curious about the underlying threat in the film. There is obviously some sort of plague that they are protecting against, but it seemed to me like there was some sort of other element that is hinted at but never quite addressed.
The title of the film for example seems to hint that there is some kind of physical threat which only comes at night time, and the family even has a rule of not going out at night. In the dream/memory sequences of the son Travis, he goes out and sees something which terrifies him.
So was there some threat other than the plague? Some kind of monster or carrier of the disease?