This was one of the first DVDs I ever bought, and it's still well-played! This tale will grip you right to the end, but, I have to warn you - you must pay attention right from the get-go, even listen to the radio news headlines in the background!
The scenario is fairly credible and the whole story is well-acted, with a great contribution from the late, lamented, Denholm Elliot in his "morose" mood. You can purchase this movie with no fears that you're wasting money - in fact, I urge you to invest!