Boarding a luxurious motor home, two married couples set off from Texas to Colorado for a little vacation fun. But instead they stumble on a group of Satanists engaged in the middle of a bloody sacrificial ritual.

Spotted by the creepy ne'er do wells and tagged as liability witnesses, the likable four then find themselves in an all-too-real race for survival.

Will the devil cult make mince meat out of the four helpless suburbanites?

A great cast (character actor Oates is excellent here, while Parker and Swit are always believable) propels this taut suspenser forward at a nice clip, punctuated by some well done chill sequences.

Lesson learned here: it is not easy batting devil worshippers off the back of your RV. Whew!

Best scene? The truly unforgettable downbeat ending that showcases the unflinching grit of the '70s with style and aplomb.