A group of investment speculators try to talk scientist Gerry Farrell (Berger) into selling them the rights to a new formula, while at a wild weekend retreat on an isolated island. As the competitors try to cheat one another with secret bids, Farrell seems disinterested, and tempers rise with the stakes. The wives and girlfriends along for the fun and games feel the tension as their men stray, or try to get them to use sex to close a deal. But once the murders begin, the possibility of anyone trusting anyone is left far behind. Allegedly a professional assignment given Bava with just two days' notice, the film is a fair murder mystery in which even this director's visual tricks can't sustain interest. The cast of connivers is interchangeable and hard to keep straight, and in some cases more easily identifiable by their now-hideous 1970 fashions than their faces.