What is so good about Detour, and why is it one of the best film noirs? It could all be in the outrageous coincidences which power this best film noir to its crazy end, as summed up in the film's final words:
Fate or some mysterious force can put the finger on you or me for no good reason at all.
Detour is tawdry, complex and revels in pessimism and doom, and the incessant confessional narrative just ramps all of this up into something that is fascinating, simply because the characters are so hopeless, and so vile.
The low budget as it happens makes it all the better, with most of the action taking place within the claustrophobic confines of a car, and then a hotel room. It's a story of failure, told by a failure, and the darkest noir elements can surface freely and float in this environment, like turds on the surface of a swamp.
Just look at that hangdog expression that Tom Neal wears. It never leaves his face throughout the picture, and that indecision, the fate that leads him into the truest of film noir territory, is one of the best examples of noir out there. Time after time, he redirects his repressed emotions into crime, and if there is a message, a doom-laden and typically film noir directive, it is that morals are not as simple as they are often made out to be in the glorious tapestries (of lies) that Hollywood presents.
Al and Vera are the very opposite of what an American couple should be. They are deceitful, in denial, and play off each others' hate so much that it becomes a tense race to the bottom, to see who is going to crash first, whose greed and weakness is going to result in death, or arrest. Both Al and Vera, bound by their chains of guilt and greed, drag each other down, making Detour not so much a detour as a descent into the blackest heartland of film noir.
