49th Parallel Thursday 17th December (1998) 10.30am BBC2

No-one made a greater variety of unusual and important movies about the Second World War than Michael Powell and Emeric Pressburger, and this combination of propaganda and suspense is one of the oddest and most affecting.

Early in the war, a German submarine is sunk off the coast of Canada, and the fanatical Nazi commander (Eric Portman) tries to lead his crew across the border to neutral America. The German group are whittled down - when a gentle baker wishes to 'defect' to Anton Walbrook's religious community because he has developed an understandable crush on Glynis Johns, Portman has him shot - and run into a series of characters who represent the allies:

Leslie Howard perfectly encapsulates the diffident but indomitable Englishman, Laurence Olivier is somewhat less well cast as a moustachioed French trapper and Raymond Massey delivers a coup de grace as an American GI obviously keen on getting into the fight early by beating up the Nazi in a freight-car as he tries to escape into the then-neutral United States.

Shot on location in Canada, this was unique in its day for making the 'enemy' the central figures in the drama - there were a lot more movies about downed allies escaping through occupied Europe than there were like this - and trying to analyse just what it was we were supposed to be fighting for and against.