The children learn that Grainger and Miss Millington are simply blackmarketeers rather than spies. Norman and Mary try to call the police from Westbourne Hall, but are caught by Grainger and Millington and locked in a shed. Seeing them captured, Polly goes off to find a phone, only to bump into Vivienne Belling. Polly attacks her, but is stopped by Mike. Polly leads them to the quarry where Dennis has managed to free Norman and Mary, who trap Grainger and Millington in the shed. The blackmarketeers are arrested, and Vivienne Belling reveals she was investigating Grainger the whole time. Mary is moved to Wells Farm and the charges against Luigi are dropped and he returns to work on the Farm. Norman's mother arrives at the Farm to take Norman home. In the present, Norman is finally reunited with Polly.