I think that the "child drowning in the mill run" might be from The Eagle Has Landed, where a team of German paratroopers have been sent to assassinate Churchill in 1943. They are disguised as a Polish paratroop unit (to avoid difficulties with the language) and are waiting in a village where Churchill will spend the night. While they are conducting "maneuvers", a village child falls into the mill race and is rescued by one of the Germans, who is killed, and whose uniform becomes visible.
The film also deals with Ireland, in that the Germans are getting help from an IRA man who makes his way from Germany to Britain by being dropped into the Irish Republic by parachute and then making his way across the border into Ulster.
It's a pretty good film (although the book is better.)
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