Fear of God (Part 3)

Paul is 'attacked' by a mysterious noise in his flat, but manages to make a recording of it before finally passing out. He feels there's a link to this and the 'music room' of the Regiment of God mentioned in Ros's diary - and also notices he's being covertly followed by cult members. He and Nicola track down Rosamund's boyfriend, and they all travel to the cult's HQ to try to find out the truth about her and the music room.