Well the way i see it, a cliff hanger is everything that does not finish a story and leaves something in the middle and you have to wait a whole season to see what will happen.
DO NOT READ BELOW IF YOU HAVEN’T WATCHED SEASON 4
.
.
.
.
.
.
.
.
.
Without knowledge of the books or reading anything whatsoever on the internet, something tells me that Jamie will try to help his brother and probably get himself killed. This is pure speculation though, knowing how utterly stupid and perverted G.R.Radly is.