Mercier along with Halbach travel to Berlin via Czechoslovakia, he gets the information that he needs, and feeds it back to his superiors, unfortunately they can't contemplate the reality of Germany attacking France.
Mercier seems to continually prove beyond doubt that Germany is preparing for war, why on Earth are they so blind to the facts and even video evidence?
Tennant is terrific throughout, so impressive how you can visibly see Mercier's terror and frustration, how he can foresee the tragedy of war, whilst others continue in ignorant bliss.
There was one scene in particular that struck me, where Mercier is in Berlin sat on a park bench, watching The Berliners very happy in everyday life, he can see exactly what's brewing.
Exceptional. 9/10