I suppose in 1948 you could get away with plots like this - a sort of insipid Ball Of Fire with all the pith removed. A group of dull academics marooned in a drab edifice and badly in need of a catalyst, ideally one who is young, virile, hairy-chested but sensitive with it. Enter David Farrar, who blends into the landscape like a Moog Synthesiser in a string quartet. As we've already established the locale as Improbable-On-Sea there is, in situ, a resident sex object in the shape of Greta Gynt, a good thirty years younger than anyone on the faculty and seemingly happy as a sandboy with no romantic prospects in sight. Before you can say plot device she and Farrar (Mr. Trail) are an item, to the chagrin of Marius Goring (Mr. Perrin) who had an active fantasy life involving Gynt, It ends in tears, natch.
Review of Mr. Perrin and Mr. Traill
