Bonus: Ex-Head of MI6: How Russian Spies Likely Got Caught in UK

After a major national security investigation into Moscow’s espionage efforts, Great Britain unmasked an alleged Russian spy ring. Three Bulgarian nationals suspected of working for Russian security services were charged with possessing numerous forged identification documents. On this week’s bonus episode, Julia Macfarlane asks her co-host and former MI6 Chief, Sir Richard Dearlove about how the alleged spies likely got caught and speculation the trio may have been sleeper agents.