Proud Helios — Melissa Scott

The free flow of traffic to the Gamma Quadrant is vital to the recovery and survival of the planet Bajor and to Federation interests as well. When a mysterious cloaked ship begins raiding wormhole shipping, cleaning out holds and killing entire crews, Commander Benjamin Sisko of Deep Space Nineâ"¢ acts at once to stop the menace.
Commander Sisko has unexpected aid: the cloaked vessel has been striking Cardassian ships as well, and the Cardassian commander Gul Dukat intends to destroy the ship at all costs. Their unlikely alliance works well -- until two of Sisko's crewmen are captured by the raiders. Gul Dukat will stop at nothing to gain his victory; now Sisko must locate the predator ship, hold off the Cardassians long enough to rescue his people -- and prevent an interstellar war!