By Treason's Tooth

Navy Lieutenant Tran Van Mihn usually faces the world with a shrug and a smirk, but he can't just stand by and let an innocent man, even a dead one, be accused of sabotage.
The USS Chester Williams cannot sail because someone has smashed a console of essential pressure gauges. Tran, the ship's Operations Officer, is assigned to conduct the required investigation. The ship's Captain, livid over this smear on his vessel's reputation, pressures Tran for a quick and tidy conclusion. Tran tries to comply--he just wants to get the thing done--but the evidence he finds is anything but neat and tidy. There seems to be more at play than a disgruntled sailor.
Repaired, the ship gets underway, and a man is lost overboard under suspicious circumstances. An agent from the Naval Investigative Service, on orders from higher command, comes aboard to complete the investigation. The agent does so and names the lost sailor as the saboteur, much to the Captain's satisfaction. Tran, however, is convinced this is not true. He disregards direct orders and, at risk of his career, continues his now unauthorized search for the truth.
But someone else is concerned about Tran's refusal to back off from his suspicions; someone with murderous intent. Soon Tran finds more than just his naval career in jeopardy.