The lavish marbled interior shots of the Russian Embassy were filmed within Glasgow City Chambers. The Chambers offers free guided tours to members of the public most days.
Set in and around Greenwich, London, England, "The Secret Agent" was filmed in and around Edinburgh, Scotland and Glasgow. Edinburgh is a film-friendly city and Scotland is home to a great enthusiastic crew resource.
The train seen in the 2nd episode was the 62712 Morayshire built in 1927 at Darlington to a Nigel Gresley Class D49 design. D49 locomotives were named after fox hunts and shires. She forms part of, and was maintained by Bo'ness & Kinneil railway.
This is the fourth time that Joseph Conrad's novel has been adapted for the BBC.
David Suchet (who Toby Jones worked with in an episode of "Agatha Christie's Poirot" (1989-2013)) appeared as Adolf Verloc in the 1992 mini-series adaptation of Joseph Conrad's novel.