|UK||2015||60||Drama . Crime . Adventure . Mystery|
Major Carter gives Tommy a mission he must keep completely secret, even from Tuppence. There has been a leak on the Third Floor and Tommy is the only man Carter can trust. Gilbert Worthing was working on a top-secret prototype for a nuclear bomb, has gone missing from a military base in Cromer, along with his work. Tommy has to work undercover in disguise as a birdwatcher to Cromer, in an effort to identify which guest at the Sans Souci is holding the British government to ransom.
|Episode Title:||In N or M?|
|Airs:||2015-08-16 at 09:00 pm|