This episode takes place in 1904.
One of seven espionage related filmed productions featuring actor David Suchet which were made and released around the mid 1980s. The titles include Gulag (1985), Trenchcoat (1983), Red Monarch (1983), A Song for Europe (1985), The Falcon and the Snowman (1985), John le Carré's The Little Drummer Girl (1984), and an episode of Reilly: Ace of Spies (1983) [See: Prelude to War (1983)].