Proud Helios (Star Trek Deep Space Nine, No 9)

The varied occupants of the Deep Space Nine space station must cope with a powerful and very hostile invisible warship, and Commander Sisko joins forces with the Cardassians to stop the mutual menace. Original.

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, so when a mysterious cloaked ship begins raiding wormhole shipping, cleaning out holds and killing whole crews, Commander Sisko of Deep Space Nine acts at once to the stop the piracy. He soon finds he has unlikely help, since the cloaked ship has been preying on Cardassian ships as well, and the convenient alliance goes well until two of Sisko's personnel are captured by the pirates. The Cardassian commander will not hesitate to destroy the pirate ship if he can, even if Sisko's people are still aboard, and Sisko must find the pirates first and hold off the Cardassians at least long enough to bring his crewmen to safety.