It turns out “boffin” used to be military slang referring to a puffin, something you’ll learn early on in this amusing wartime story. The film centers around a group of top-secret inventors tasked with developing a portable radar system for planes. Stationed at a secluded RAF base, "Prof. Heatherville" (played by Ralph Richardson) guides a rather unusual team, who face doubts about why they aren’t actively involved i…