The Tomed Incident was a terrible confrontation between the United Federation of Planets and the Romulan Star Empire in 2311 that cost thousands of lives. The incident led to the signing of the Treaty of Algeron, which banned Federation research into or use of any cloaking device, and led to the withdrawal of the Romulan government from interstellar affairs until 2364. (TNG: "The Neutral Zone", "The Pegasus", "The Defector"; ENT: "These Are the Voyages...")
The Tomed Incident was the primary focus of the Lost Era novel, Serpents Among the Ruins. In the novel, the warbird Tomed crashes into an asteroid, housing a Federation base, at high warp, and because the containment of its quantum singularity had failed, the massive explosion which results distorts the fabric of spacetime and wipes out numerous Starfleet outposts, as well as the USS Agamemnon. However, while the "official" casualties (including Esteban Rodriguez and Tom Paris's grandfather) number in the thousands, the actual death toll is six, all Romulan; the Agamemnon and the bases were empty, rigged to emit false lifesigns, the thousands of Starfleet personnel listed as killed in the attack already dead - their deaths in the past year having been covered up - and records fabricated to appear that they had been stationed there.
Summary: The year is 2311. It is a year of infamy, a year that later generations will remember as one that altered the course of history at the cost of thousands of lives. It is the year of the Tomed Incident, and its tale can at last be told. In the midst of escalating political tensions among the Klingons, the Romulans, and the Federation, Starfleet goes forward with the inaugural flight of Universe, a prototype starship that promises to revolutionize space exploration. But the Universe experiment results in disaster, ravaging a region of space dangerously close to the Romulan Star Empire, apparently confirming suspicions that the Federation has begun testing a weapon of mass destruction. As the military buildup accelerates on both sides of the Romulan Neutral Zone, Captain John Harriman of the Federation flagship USS Enterprise-B is fated for a final confrontation with his oldest enemy at a flashpoint in history – with the Beta Quadrant one wrong move from the outbreak of total war.
