Roger Marsh (Peter Fonda) and Frank Stewart (Warren Oates) are living the dream: two successful motorcycle dealership owners from San Antonio, heading out for a ski trip in Colorado with their wives, Kelly (Lara Parker) and Alice (Loretta Swit), in a luxury RV. But when they decide to boondock in a remote Texas meadow, their vacation hits a hard turn into the occult. They witness a gruesome human sacrifice across the river, and once the cultists realize they’ve been spotted, the vacation turns into a cross-state game of cat-and-mouse.

You couldn’t ask for a better duo to anchor this madness than Peter Fonda and Warren Oates. Fonda brings that rugged, cool-under-pressure vibe, while Oates, a true character actor legend known for his work with Sam Peckinpah, adds a frantic, grounded intensity that makes the stakes feel real. They were real-life friends, and that chemistry shines through even when they’re dodging fire and shotgun shells.

The wives aren’t just passengers, either. Loretta Swit (iconic as Hot Lips Houlihan on M*A*S*H*) and Lara Parker (Dark Shadows) handle the escalating dread perfectly, turning from vacationers into hardened survivors. And let’s not forget the great R.G. Armstrong as the local sheriff. If you’ve seen your fair share of B-movies, you know Armstrong is the king of the is-he-or-is n’t-he trustworthy authority figure.

From here, it turns into an absolute nightmare. The wives find weird occult runes, the local library is a gateway to dark knowledge, and there’s a mysterious red truck tailing them everywhere they go. By the time they hit an RV park, the cult is already inside the house. Well, inside the RV’s cabinets, where they’ve planted rattlesnakes. When the group realizes that the sheriff, the locals and every roadside stranger are seemingly part of a vast, satanic cabal, the ski trip is officially canceled. It’s a high-octane, pedal-to-the-metal chase across the Texas badlands, leading to an ending that will leave you staring at your TV screen in total disbelief.

Note: If you love dogs, as I do, the fate of Ginger is not a happy thing.

Lee Frost was originally at the helm, but after Fox execs caught wind that the actors were basically improvising the whole script, he was swapped out for Jack Starrett. Fonda and Oates almost walked away, but they stuck it out, and the resulting friction actually adds to the film’s manic, desperate pace. As for Starrett, he loved a good headline and famously claimed he hired actual Satanists as extras. Whether that was just classic drive-in marketing hype or the truth, the eerie, blank stares of the cultists in the background of almost every scene sell the paranoia perfectly. Then again, if it were real Church of Satan members, you know that Anton LaVey would have hyped that up as he did with Asylum of Satan and The Devil’s Rain.

The New York Times said, “This is a ridiculous mishmash of a movie for people who never grew up, which is not to say it’s for children. One would think that Mr. Fonda and Mr. Oates had better things to do, but perhaps not. American movie production is in a bad state.”

Whatever, fancy paper. This is RV horror at its finest.