I thought Stefan told someone (Adam?) that he wanted to tell him something important but then disappeared. Rob must have been still around as he later insisted that Stefan had gone home (because his mother was ill) but there was no way anyone (except Rob himself?) could contact him. It was about the time that Charlie was sent north too I think.
PS Nfk - My memory is far from perfect. Where are the old episodes available?
Angela Rayner lashes out and calls Sunak “pint sized loser”.