Strange Visitors & Other Tales (2001)

Three bondage-filled vignettes from Harmony Concepts. In the first two beautiful aliens, one good and one evil, keep a lovely Earthling bound and silenced. In the second, a scientist discovers that a certain machine generated tone causes a woman to demand to placed in bondage. In the third a secret agent and her victim are both the victim of a rival third party who leaves them securely gagged and bound.