Heaven Knows, Mr Allison tells the story of Corporal Allison (Robert Mitchum), a marine who drifts to shore on a Pacific island to find that the only person there is Sister Angela (Deborah Kerr), a nun who has just buried the priest she accompanied to the island. They make plans to escape the island but these turn sour when Japanese troops turn up to make a base on the island. They are forced to seek refuge in a cave and see what happens next but the close proximity causes its own problems.
There are a few similarities in tone between this film and The African Queen (1951, reviewed here) but any notion of a love plot is complicated by Sister Angela's habit. The romantic tension between Mitchum and Kerr works a little but can't last. Essentially, we have to care about their survival and not any hope of a romantic conclusion. The film achieves this, in part, by making Cpl Allison a good, down to earth man who has no pretensions of intelligence. This role was the first of Mitchum's that I've had no problems with but it suited him perfectly. As for Kerr, her Irish accent did get a little grating at times (and some words got lost) but her best moments came as Sister Angela finally cracks while a drunk Allison is arguing with her. The veneer of calm she's managed to maintain throughout makes this moment all the more compelling.
The third star of the film is undoubtedly the setting. Beautifully directed and filmed on location, the island comes to life, playing an important role as the film progresses. Heaven Knows, Mr Allison is a decent film hampered partly by a bad title. It's worth a watch as an excellent Robert Mitchum film and as part of Deborah Kerr's catalogue of good performances.