In this year’s final episode we delve deep into the world spies: couples sent to act as sleepers in foreign lands, living among the locals until called on to act. How are they selected, are they match-made or recruited as couples, and what are the pitfalls of life as an “Illegal”? And what does David know about a surfing sleeper cell on the Northern beaches? Dust off your wedding ring and prepare to renew your vows - Children optional.