Cosia is one of three female aliens who accidentally crash land on Earth. They hide their presence by kidnapping 3 men and a woman who witness the crash, and plan to hold them until they can make reparis and leave.
Cosia is the ships scientist and doctor aboard the space ship, who is run by the captain who is known as the Skipper (Kate Ferguson) and Partha (Ava Cadell), who works the engines. Cosia is seen wearing several different sexy outfits, while the others do not change their attire. Cosia also spends quite a bit of time getting around the ship on a pair of roller skates.
The female aliens are curious about the men species in particular, since this is their first encounter with them, coming from an all female planet. They therefore, experiment with human reproductive techniques with the three men.
In the end, they return all the earthlings to Earth and release them, but convince Willy (Tony Maiden) to stay with them. However, while Willy is having sex with The Skipper, the spaceship blows up, ending the movie and the lives of the lovely aliens.