Cottage to Let

Cottage to Let is a 1941 spy film starring Leslie Banks, Alastair Sim and John Mills. Set in World War II Scotland, its plot concerns Nazi spies trying to kidnap an inventor.

It turns out that there is cause for concern German agents kidnap Barrington. Ronald stows away in the car used to take the captive to an isolated water mill. When Perry shows up, Ronald attacks one of the spies to help in the rescue. Unfortunately, it is all in vain, as Perry is revealed to be the ringleader. Perry intends to take Barrington to Berlin on a seaplane which is due to arrive the next night.However, Dimble turns out to be a British counterintelligence officer. He manages to infiltrate the ring and learn where Barrington is being held. All but one of the spies are captured and the prisoners are freed. Perry initially escapes, but is eventually tracked down and killed in a shootout with Dimble. ........

Source: Wikipedia