Colonel Williamson, Air Force retired, was on his last legs, but he could still fly a plane, and in the Alaska wilderness, when something went down, you pitched in. Williamson had a knack for finding lost things which served him well on rescue flights. He called in, took a quadrant, and began the hunt.
The alien ships computer sensed the nearing presence and powered up its medical unit. Hopefully the HUMAN Williamson could be made to bring his captain to the medical unit to preserve whatever life was left. When the HUMAN stepped inside, the computer sent a mental probe, possessing him in order to perform its task. Sadly, the captain had been exposed to the elements for too long; her body was not revivable.
Salvaging those memories and traits that it could, the computer scanned the HUMAN to see if it could be used. It found that the body was suffering illness and degeneration, but was reparable. Having the human disrobe, the machine made him climb onto the healing array, and began to change him. Naturally, since the captain was female, the HUMAN would be changed to female as well.
A glowing light engulfed Colonel Williamson, morphing his body into a young healthy female form, no longer entirely human, and a new hybrid person was born.
Colonel Williamson, Air Force retired for medical reasons, was the man who discovered the downed alien scout ship in the Alaskan wilderness. Well, he had been a man. The ship’s automated medical unit had used his body in an attempt to save its female alien passenger. He vaguely remembered carrying the woman’s body into the remains of the ship before passing out.
He had awakened changed, his sick old male body completely gone. Now, she was a tall, well built redhead with green eyes that glowed faintly, and some kind of green energy that played about her hands. And, she had strange fragments of memory, flying the scout ship, remembering a daughter at home, and the pleasures of sex.
The medical computer had healed them as best it could, and then sent Arma / Williamson away from the ship before self destructing. The merged colonel had no choice but to fly back to his home and try to put some kind of life together. She supposed she could conceal the facts of Williamson’s disappearance and keep drawing his retirement pay for a while.
In the meantime, she was healthy, fit, and craving sex like some kind of addict; time to see if she could make out with the human race.