剧情：
Episode1-TheEternityRing
MI5suspectsBritishatomicresearchhasbeeninfiltrated,andaskFoyletoinvestigatewhetheraRussianspynetworkcouldbeatworkintheheartofLondon.
Episode2-TheCage
Foyle’sinvestigationintothedeathofanamelessRussianleadstoamysteriousmilitaryfacilityandthediscoverythatthevictimwasaspywithdangerousconnectionstoBritishintelligence.
Episode3-Sunflower
ProfessorPeterVanHarengivesalecturetoagroupofstudentsontheself-portraitsoftheartistRembrandtandcausesayoungmantosufferafrighteningflashbackwhichendsintragedy.