The Shade Trilogy Series by Nicholas Yermakov, Simon Hawke

Boomerang--an untouched pastoral planet: on the surface it seems a perfect candidate for human colonization. But first a Colcom survey team must make contact with the Sades-=the humanoid-looking natives of Boomerang--and determine whether they are animals or intelligent beings. However, the Sades appear to have no interest in the survey team. Mot, at least, until the day that pilot Shelby Michaels encounters a mortally wounded Shade... moreBoomerang--an untouched pastoral planet: on the surface it seems a perfect candidate for human colonization. But first a Colcom survey team must make contact with the Sades-=the humanoid-looking natives of Boomerang--and determine whether they are animals or intelligent beings. However, the Sades appear to have no interest in the survey team. Mot, at least, until the day that pilot Shelby Michaels encounters a mortally wounded Shade. Then, in a totally unexpected way, contact is finally established, and for Shelby there is not going back. less

The Earth's Directorate sends an expedition to the planet Boomerang in search of the secret of the race of Shades' immmortality.

What was the secret of the Shades?Boomerang - pristine, lush, and verdant, with a tumbling, crescent moon that gave the world its name. It seemed perfect for human colonization, but the dominant form of life were the elusive Shades, who looked almost like humans, but behaved and lived like animals... moreWhat was the secret of the Shades?Boomerang - pristine, lush, and verdant, with a tumbling, crescent moon that gave the world its name. It seemed perfect for human colonization, but the dominant form of life were the elusive Shades, who looked almost like humans, but behaved and lived like animals. Were the Shades intelligent beings, or were they beasts?Before colonization could begin, the survey team had to find the answer to that question, but the silent and mysterious Shades showed no interest in the humans. Not until the deeply troubled mission pilot came upon a dying Shade and first contact was established in a way no one could have expected. And Shelby Michaels, her sanity already hanging by a thread, would never be the same. Not after she took part in the Last Communion . . .. less