"Hide and Shriek"
Rod Steiger, Yvonne De Carlo, Michael J. Pollard, Sarah Torgov, Fiona Hutchinson, William Hootkins, Terry Kelly, Mark Ericksen, Caroline Barclay, Mark Lindsay Chapman
Three couples headed for a vacation are instead stranded on an island and captured by a demented family headed by Steiger and De Carlo, a scary enough proposition in itself. Even worse, Ma and Pa have three middle-aged moronic offspring who still dress as children and are intent on killing the thwarted vacationers (who are none too bright themselves) one by bloody one. A stultifying career low for all involved.