The Swamp(1973)

Lena, Alexis and Manolis are ready to run with the money of a bogus company they had founded, when Lena discloses the secret to her childhood friend Dimitris. Alexis and Manolis decide to take him along, in their small private plane. They will land in a deserted spot and try to kill him, while Lena escapes with the plane, which she throws to a swamp along with the money it carries. The people from a lighthouse nearby apprise of the situation and try to get the plane out of the swamp, hoping the money will change their fortune.