That was poorly conceived. They'd have to keep those things stored somewhere for as long as the spy was active. What if a rat ate the last Mars bar at 6:00am?
Obviously HN always knows better, this reminds me of the Dropbox post.
There's a great book that covers every single aspect of this escape, "The Spy and the Traitor" by Ben Macintyre. Rest assured that the British embassy had plenty of Mars bars and Harrods bags for this signal!
