What Time Does the Balloon Go Up? - S3-E24
Continuity mistake: When the British spy is trying to get to the camp, the area around him seems fairly lit, as at dusk, after the sun just set. When he glances toward the gates, the sky is black, suggesting night (the shot of the gate is stock footage). When the shot goes back to the spy, it's dusk again.
Answer: It's a solitary cell. Steve McQueen, star of 'The Great Escape' is known as the 'Cooler King'.