Never expected the twist at the end, though old Jed usually has one up his sleeve. Very understated acting performance by the timid little victim/'engineer and Jihadi'. Watching her turn from mouse to lion was like watching Jekyll turn into Hyde. Brilliant series and, like many on here, i look forward to next year's return of Line Of Duty.
I'll be there! Are we allowed to speculate? Does anyone else have a cunning idea of the culprit or does crystal ball gazing come under the heading of spoilers?