The Mystery of Planet Wer

The colony planet, Wer, had a mystery. Why it is the way it is? Wer earned its name when it was discovered that the colonists could change into a wer-animal of one sort or another. Lieutenant Justin Radolfuss, who worked aboard a space ship as an engineer, was a rare example of a citizen of Wer; he worked aboard a spaceship where human form was not an option. One of his duties was answering the questions of the passengers as they came into orbit around his home.
It was his task to discourage tourists from traveling to the surface for the fun of it, and he did it every time his ship came into orbit. You see, after one travels to the surface, if they leave again, the change is permanent; it would be a little difficult to explain to your mother why you now looked like, say, a hyena or perhaps a bear. Such an appearance might be fun during Halloween, but just try to get a job as a waitress dressed up in a wolf's costume every day - one you couldn't take off.
One could be human only on the surface of Wer and nowhere else. As his ship entered orbit around Wer, Justin held his question-and-answer session until no more questions were forthcoming. This time, after everyone else had left, one woman remained behind; she was blind, and though she had heard it all, she couldn't see any of it, so she wanted to touch him. As Justin showed her around the ship, he fell hopelessly in love with her.
As was his habit, he would go on leave during their stay. This time, he would have remained aboard, forgoing the pleasure of seeing his human face in the mirror for a while in favor of spending more time with this most captivating creature, but this time, he had passengers - he had to go - he was the pilot. Once they'd landed, after seeing Robin Dupree in the capable hands of her chaperone, Justin answered a summons to his father's home.
When he got there, he learned that his father was dying and it seemed that the rest of the family hadn't noticed. Justin's father, Isaac, was going to finalize his will and he wanted Justin, the only engineer in the family, to take over the core family businesses and responsibilities. Justin's two eldest brothers, who expected that inheritance, would get nothing more than they already had; it just wasn't sound business.
And thus was the beginning of the troubles, or at least that was when Justin became involved. Someone, it appeared, wanted the head of the family dead. At first that was Isaac, but then it became Justin, and in the midst of it all they went in search of the planet's oldest mystery. Could they sold if before someone killed them? And what exactly was the mystery anyway?