Having long been interested in watching this well-regarded British thriller of the 'let's-drive-an-heiress-mad' variety, I can't help admitting I was somewhat underwhelmed by it; the reason for this, perhaps, is that we've seen this plot in countless other films so that, while one hoped that the treatment would rise above the overly-familiar premise, what we get here is pretty standard (read: low-key or, if you like, genteel) stuff. That is not to say the suspense of the piece and the awkwardness that goes with it (the heroine trying time and again to convince the police that the man who says is her brother isn't really) isn't effectively rendered, far from it. For one thing, the consummate professionalism and no-nonsense attitude of the people involved (despite the modest resources at hand) is redolent of classic British cinema at its best and the casting, while unlikely at first glance, is quite successful in the long run. Anne Baxter is the put-upon heroine, Richard Todd the smooth intruder (who goes so far as to acquire the daredevil driving skills of Baxter's allegedly deceased brother!), Herbert Lom the Spanish Police Commissioner (the film is set in picturesque Barcelona) and Alexander Knox appears as Baxter's apparently duplicitous uncle. All of this converges satisfactorily in the film's twist ending and its real coup which not only subverts everything that has gone on before, but would be too far-fetched to swallow had one not been sufficiently drawn into the intricate proceedings.
