Star Trek: The Next Generation: Slings and Arrows, book 2 : The Oppressor's Wrong
Phaedra M. Weldon2007

The USS Enterprise-E is assigned to ferry demolition experts from Deep Space 9 to Starbase 375, but just as they arrive. Admiral Leyton declares martial law on Earth and the Federation is put in a state of emergency. On the starbase, Admiral Hahn has gone missing, and there are several unexplained events – and one of the demolition experts, Lieutenant Daniels, isn't convinced that it's necessarily Dominion treachery. Picard and the Enterprise crew must learn the truth – about the martial law declaration and what happened to Admiral Hahn – before the Enterprise itself becomes the next casualty...