If you occasionally have a spare Sunday afternoon, you may have seen Ice Station Zebra. Padded with commercial breaks, the thing could go for three and a half hours. If you are Howard Hughes, you may have watched Ice Station Zebra on a continuous loop in your fortified suite at the Beverly Hills Hotel. Watching ISZ, as we in the industry call it, one can see why it endures, both as a certain type of man-entertainment (dad movie) and as a maddeningly flawed piece of cold war flimmaking. I call it a dad movie because it lays out a mysterious destination. The first part is getting there. Once there, the task is to find a canister of film before the Russians can. It's literally a movie about doing two things, and some psychological compulsion forces us to watch until the end. You don't really buy Rock Hudson as the captain of a US nuclear submarine. Ernest Borgnine does not really sell the charming Russian turncoat routine. There's no deep real character work, the stakes don't seem all that high. The end fizzles out in a stalemate with a low body count. So what makes Ice Station Zebra so watchable?