This time we're uncovering the origins of espionage-related terms, from bug, alias, and surveillance to eavesdrop and secret, tracing how they entered the English language (and words they are related to). Staying under the radar is a classic spy skill - the word radar began as an acronym for radio detecting and ranging. Discover why James Bond's watch of choice is named Omega, and learn about the earlier names and organisations that eventually became MI5 and the CIA, the British and American intelligence services. Also explored are the English terms that shares linguistic roots with the French jeu de cache-cache and the Spanish el escondite, both names for the childhood game hide and seek.