What a terrific little film this is. Made in 1973 on what was presumably a very low budget, this two-hander about a pair of research scientists experimenting on apes in a remote mountain science station is a lean and mean horror-thriller, put together with maximum conviction, a haunting atmosphere and stratospherically good performances.<br /><br />Robert Culp and Eli Wallach brilliantly portray the disintegrating relationship between the two men, as each comes to suspect the other with tampering with the heating systems, despoiling the food, and generally fouling things up.<br /><br />Having discovered the previous lone occupant of the research outpost frozen to death, it seems something very sinister is haunting the men. What could it possibly be? I won't spoil things by revealing the solution to the mystery - it works extremely well, and the moment when the nearly frozen Culp manages to get back into the station and confronts Wallach, axe in hand, is one of the classic scenes of horror, t.v. or otherwise.<br /><br />It's a film which draws you in gradually, relying on small moments to unsettle and rivet the viewer. This in its own way is as good as Spielberg's Duel. A treat for a first time viewer.<br /><br />Please, please, please somebody somewhere get this released on DVD. One of the best things ever produced by the medium, it deserves remastering preservation on a grand scale.