Unbroken Bonds. Starfire Angels: Forgotten Worlds, #14

Ann and Nik's wedding is supposed to be a joyous occasion. However, they and their friends have underestimated their enemies, and even worse, their supposed allies. In the midst of the celebration on Ethal, L'Ni is taken with few clues about who or why. When L'Ni awakens chained in a dark chamber, too numb and weak to free himself amid the torture by his captors, he soon realizes his fate. The methods to subdue him could only have been advised by his own people.
The Issa Pralemmar want their heretic and will do anything to capture him. L'Ni's friends are determined to find him. Through memories and clues, Nya and the others must solve the mystery of his disappearance and locate him before it's too late, but as the pieces come together, they soon realize the full threat to Ethal.