Second Nature (Star Trek: Seekers, #1)

The first in the Star Trek: Seekers series, building up on the story of the Vanguard series.

The Taurus Reach. Once the conquered realm of a powerful alien species, this region remains largely shrouded in mystery even as it brims with potential for exploration and colonization. The Federation has sent in two of its finest starships on a quest to uncover the secrets it may yet hold...

The Tomol are a primitive civilization occupying a lone island on a remote world. Their culture is an enigma, centered on every member's commitment to a painful, fiery self-sacrifice upon reaching maturity. But one of their clan has shunned this obligation, triggering a transformation into a new, powerful life form. Answering the distress call of the USS Sagittarius–which has crashed on the planet following a fierce battle with the Klingons–Captain Atish Khatami and the crew of the Starship Endeavour must now attempt a rescue mission... even as they are locked in battle with the evolving, increasingly malevolent Tomol who, if allowed to escape their home world, pose an imminent threat to the entire galaxy!