Cloak (Star Trek: Section 31, #1)

They are the self-appointed protectors of the Federation. Amoral, shrouded in secrecy, answerable to no one, Section 31 is the mysterious covert operations division of Starfleet, a rogue shadow group committed to safeguarding the Federation at any cost. Once, in order to preserve the galaxy's fragile balance of power, Captain James T. Kirk carried out a dangerous mission to capture a cloaking device from the Romulan Star Empire. Months later, while investigating a mysterious disaster aboard a Federation starship, Kirk discovers that the same technology he obtained for the sake of peace is being put to sinister purposes. What the crew of the "Starship Enterprise(TM) " uncovers will send shock waves through the quadrant, as Section 31 sets in motion a plan that could bring the major powers of the galaxy to their knees.

NO LAW.
NO CONSCIENCE.
NO STOPPING THEM.