Wearing only period dress from the 1940s, the recruits travel to a remote estate where four are eliminated after a rigorous selection process.
The remaining hopefuls train in skills with guns, explosives and hand-to-hand combat, while some of the SOE's most audacious missions are recalled.
The students reach the survival training phase in the Scottish Highlands, where physical obstacles and discomfort take a toll on their abilities.
Lock picking and sending coded messages are among the skills the students learn at Finishing School, where they also face intense mock interrogations.
Only six recruits remain to face the Final Scheme, a 24-hour rehearsal mission that will call upon every skill the would-be spies have absorbed.