Solid acting, a strong non sensational and intelligent story, a lack of unnecessary "action" set-pieces. This was a perfect, if dull (in the style, not quality sense) drama. Everything that a drama of the period needed to be.
Lead Charlie Cox as rookie spy Charles Thoroughgood, was an actor unfamiliar to me, but appearing in pretty much every scene, he gave a quality performance as the spy with a complicated history.
Romola Garai however was an actress I had been in love with since her turn in The Hour, a bright and glossy role, far removed from the dowdy, but still beautiful Anna March. In a relatively slim role, Romola did all that was required, looking mostly glum with her husband and glowing (love struck?) with Charlie.
The spy boss (either at his desk or the local cafe), Hookey, was played by the very familiar to me Simon Russell Beale, having seen him rattling off words to the dozen in the Harold Pinter play The Hot House earlier in the year. It was unusual to see this actor having less lines in an hour and half than he probably had in a minute earlier in the year. However as to be expected of such a renowned stage actor, it proved a doddle and he filled every scene he was in.
Finally Andrew Scott as the Russian spy was an interesting proposition, mainly known as the insane, squeeky voiced Moriaty in Sherlock. Hearing him deliver his lines with a strong (maybe too caricatured?) Russian accent was weird. However he was OK, although undoubtedly the weakest of the four leads.
The visual appeal of the play was exemplary, the washed out, grainy look suited the piece perfectly. Although like many of these "gritty" dramas, I really could have done without the never still camera work.
Also a special mention for the very strong music from Ruth Barrett, highly commanding when it needed to be (striding across a field) but equally contemplative when required. An aural feast!
Overall though, this was an excellent, intelligent drama, maybe not for those who have a constant need for action, but for those that require a fix away from witchetty grubs and other brainless reality shows this was the perfect antidote!
BBC iPlayer: http://www.bbc.co.uk/i/b03k3cc2/ available until Thursday 5th December 2013