1960, The Congo, and a crisis has erupted in the country where the rebel Simba army has begun to take over, causing civil war throughout the region, with all the social unrest and huge refugee problem that brings with it. Into the Congolese capital comes Curry (Rod Taylor), a mercenary, and his best friend from the Congolese army Ruffo (Jim Brown), who have a meeting with President Ubi (Calvin Lockhart) with a job for them: go to a town called Reprieve in the middle of the jungle and rescue the townsfolk there - oh, and also pick up a cache of diamonds worth a great amount of money.
Dark of the Sun, also known as The Mercenaries, was drawn from a novel by Wilbur Smith, that expert at man's man adventures based in Africa, a bestseller all over the world although some would place him a level just above Sven Hassel in terms of literary merit. That may be why his books were regarded as pulp fiction and why this subsequent adaptation garnered a snooty reaction at the time of its release, most of the criticism centering on the bloodthirsty violence the filmmakers brought over from the source. This was at a time when such action thrillers were becoming more explicit in the mayhem they could depict, something the next decade would really capitalise upon.
So if you were squeamish in 1968, you would not be found in a cinema watching this, but if you sought fullblooded derring-do to sate your jaded palate, then Dark of the Sun would fit the bill. The African setting (actually Jamaica) would appear to be appealing to those who would see the continent as a hotbed of savagery, and certainly that's the main issue those who disliked it would bring up, as if merely showing tribal violence was racist when the white characters were the focus and seen to be somehow "better" than the black ones, but actually there was a degree of far more ethical shading here than many would give it credit for. Not everyone accepted the morals, which to them looked tacked on at the end, but they were there.
This went further than simply having one nice black character and one evil white character for flimsy contrast, as although that was the case it was more complex than that. Once Curry and Ruffo board the train, they're not alone, as they have had to recruit a platoon of Congolese soldiers too, who are led by the frankly Nazi Henlein (Peter Carsten) - he is even wearing a swastika when we first meet him - and it is he who becomes the main focus for the villainy, more so than the rather anonymous hordes of the Simba who show up much later. The point of this is a battle for the soul of Curry; he's a man of violence, but he likes to think he's doing good and Ruffo is his right hand man and compass when it comes to behaving with decency and nobility.
If this is reducing a national tragedy into merely how it affects one man who's not even a native, then you could take against the film for that, but Curry remains an intriguing personality and Taylor does very well with his portrayal making a double act with Brown which could have done with a few more movies to explore (he'd already starred with harrassed female lead Yvette Mimieux). But primarily this movie's fans liked Dark of the Sun for its uncompromising action, and the set of its jaw as it went about the business of trying to stay uncorrupted while having to take part in most unsavoury dealings, which included a United Nations plane having no qualms about strafing the characters with bullets, a fight with a chainsaw which nearly sees the antagonist with his head crushed under the train wheels, a mass rape of women and men as the Simba dominate, and a final duel to the death which has Curry finally give in to the depravity he has been trying to rise above. If that wasn't shocking enough, there was always Kenneth More (as an alcoholic doctor) telling someone to "Piss off". Fine music by Jacques Loussier.