I am looking for a black and white thriller about a love triangle between two men and a woman. The woman is claustrophobic and there is scene where one of the men assumes that the other man buried the woman in a box. He digs up the box but only finds papers inside. At the end one of the men falls from a hight right into the handle of a walking stick and gets impaled by the handle, which I thought was very bizarre. It is probably a eruopean film made before the ’80s.