Originally planned as a pilot for a new television series to be called The Unknown, it was filmed with two different endings and was allotted double the normal production time. In the pilot version:
Andre reveals there is no Thanatos plant, and was thus not dead; the time tilter did not in fact work; Hobart was not dead but merely in a coma; and lastly, Kassia uses the pistol to kill Hobart, thinking he is attacking Leonora.
The other, more well-known version was shot for "Outer Limits" as episode "The Form of Things Unknown."
Note the credits animation style and music were reused for THE INVADERS scifi series. The music soundtrack by Dominic Frontiere is available from Lalaland.com, paired with another good score for the film "A Name for Evil."