The Psychotronic Film Society’s ongoing weekly series of overlooked or underappreciated features continues with a special 40th anniversary screening of the notorious low-budget blaxploitation flick “Brotherhood of Death.” This 1976 slice of drive-in theater sleaze is a steaming compote of backwoods revenge, black power rhetoric and heavy-handed political commentary that has earned a deserved reputation among aficionados of peculiar movies.

The promotional tagline for this movie was “Watch the Brothers stick it to the Klan,” and that about says it all. Three black troublemakers in a small, racist, rural community join the Army and serve in Vietnam. When they return, they set out to help empower the black population in their hometown to get organized and vote, which angers the area chapter of the KKK. Before long, the Klan are running roughshod over the local sheriff, and it’s up to the Army vets to use their guerilla fighting skills to strike a blow for integration and justice. The filmmakers had very little money to work with, and in an effort to stretch that budget, they cast NFL football players with no acting experience to play the Vietnam vets, assuming plenty of their fans would buy tickets to see their sports heroes on the big screen.

This logic proved to be quite flawed, however, and the somewhat awkward and occasionally hilarious result is a guilty pleasure of a film which displays significantly loftier ambitions than were ultimately borne out onscreen. The subject matter and graphic actions of this grindhouse-era gem are suitable for mature audiences only, while the cheesy funk music soundtrack can be appreciated by all. Showtime is 8 p.m., with $6 admission.