The Night Fighters makes use of Robert Mitchum's marvelous gift for speech mimicry as he adopts and Irish brogue for a film set in Northern Ireland in 1941. The brogue would be put to better use later on in a far better film, Ryan's Daughter.

To put in historical context, France has fallen and the British are waging war without allies on the continent for a year now. The Germans contact elements of the old Irish Republican Army and they're looking for a rising like Easter of 1916 that will drain British troops to defend the country and free the six counties who were left behind.

So the local commandant Dan O'Herlihy raises such a force in his local area and recruits buddies Robert Mitchum and Richard Harris for the group. They do a raid and one of their number is killed and Mitchum and Harris are fugitives. All the worse because as history records the Nazis never did attempt an invasion of Great Britain, they went to the Soviet Union instead.

Mitchum and Harris are a pair who would rather raise a tankard of beer than a country see this was for nothing. That leads to all kinds of complications down the road.