Another helping of sadism disguised as entertainment, “Turistas” is about a bunch of beautiful Americans set upon by psycho killers while on vacation in the Amazon. Anyone looking for a “Hostel” in Brazil? Well, here it is. You can see victims sliced, diced, skinned, eviscerated and otherwise misused in the most appalling ways, and, presumably, viscerally enjoy their suffering. Ain’t it lovely?

However, you’ll have to wait for most of the picture to unspool before it gets to the premium bloodletting. There’s fully an hour of rather dull set-up, a half-hour involving the stranding of a group of six beautiful young twenty-somethings in a remote Brazilian area as a result of an accident involving the bus on which they’re riding and another thirty minutes depicting their trek to an isolated house in the mountains under the eye of a friendly local. There are, to be sure, a few shocks along the way–the bus crash itself, an incident involving a machete and a steep cliff, an eye-gouging, and perhaps most gruesome, an “operation” on an injured scalp involving a staple gun. But it’s not until the sixty-minute mark that the real gore sets in. And even then it lasts for an oddly short time, followed by an extended underwater chase–director John Stockwell (“Into the Blue”) is extemely devoted to such stuff–that’s so visually murky and overlong that it practically brings things to a premature halt. Even aficionados of such massacre-fests are likely to find this a long slog.

But there are several other major problems with “Turistas.” One has to do with the fact that the cast of victims-to-be are not only too old for this sort of thing (high-school or college-age targets are the usual bill of fare on the menu), but make a decidedly unsympathetic bunch. The hunky hero Alex (Josh Duhamel of “Las Vegas”), is a perpetually ill-tempered sort who’s babysitting his bratty sister Bea (Olivia Wilde) and her air-head friend Amy (Beau Garrett). This trio is joined along the way by Pru (Melissa George), a colorless globe-trotting Australian who, happily, speaks Portuguese, and a couple of obnoxious woman-chasing Brits, Finn (Desmond Askew) and Liam (Max Brown). These are drab characters played by drab actors, and it’s hard to work up any concern for their fate even when they’re in the direst of circumstances.

The folks on the other side of the cultural divide are no better. Agles Steib is enthusiastic but amateurish as Kiko, the chatty local who befriends the group and directs them to that isolated house. But Miguel Lunardi is awful as Zamora, Kiko’s physician uncle and the lip-smacking villain of the piece. But it’s not just Lunardi’s terrible performance that makes his presence such a mistake. It’s the fact that his character represents the script’s effort to explain all the mayhem in an almost “elevated” way. Zamora, you see, is trying to rectify the exploitation of the Third World by “gringos” through his appalling actions. And what this absurd “justification” for his brutality proves is that people who complain about the fact that most of the slaughterers in such movies are motiveless killing machines miss the mark. It’s best to leave their motives undiscussed. Trying to do otherwise just increases the nonsensical quality.

“Turistas” was actually shot in Brazil, but with its dark, gloomy cinematography and its habit of concentrating on slums it hardly makes the locales look attractive. One can only wonder why, with its plot line about American tourists set upon by irate locals, the Brazilian government agreed to its being made there. It’s the biggest cinematic mistake the country’s endured since “Blame It on Rio.” And the Brazilians have no one to blame but themselves.