I watched the first two episodes and it’s quite close to the book. And downright marvellous in depicting the atmosphere. The fact is, that humour is a central element of this very decent thriller series. That does get a bit in the way down the line, also in the books, in spite of some shocking changes in personnel. Herron is really having fun writing these and there’s an awful lot more humour involved than there used to be in all of Len Deighton’s books together.
That said, it’s also tending to develop down a certain path one might consider ‘formulaic’ after a time*. Herron spends some effort on developing an entertaining spy vocabulary somewhere between le Carré (clear favourite), Fleming (Herron’s MI5 is located at Regent’s Park) and Deighton (atmosphere), Sandbaggers (atmosphere), Spooks (atmosphere), Queen&Country (atmosphere).
In other words, it’s a remix of the genre classics, though somewhat warped since Jackson Lamb, the central character (but not hero) of these books, was a Berlin legend - though it’s never explained what a Fiver would work in Berlin for and how apparently nothing between, say, 1990 and 2001 seems to have happened. And the years from 2001 to 2010 (when the series starts) seem to have taken place in a matter of weeks.
Anyway, this is lots of fun. I’m fairly confident this first season will be a success. Most probably the second one too. The third season ultimately will be the make or break of this, the point when the showrunners will have to decide how to create a payoff that can carry the characters over the reefs of that crucial year and into the future.
*And which series isn’t? It’s the whole point of reading a series to have familiar territory to walk your characters on.