Omega Molecule

The Omega Molecule is a highly unstable molecule thought to be the most powerful substance in the universe. Though it not longer exists in natural form, it can be synthesized by using boronite. Synthesis of the Omega Molecule is highly dangerous as there is no containment method able to contain it. Uncontained, the Omega Molecule destroys subspace, making warp travel impossible.

Theory
It is theorized that the Omega Molecule existed naturally at the time of the Big Bang, the origin point of the universe. A single molecule of Omega is thought to be powerful enough to power an entire civilization. It is not known if Omega's subspace destruction will also render subspace communications useless.

Discovery by the Borg
The Borg discovered the Omega Molecule in 2145 after assimilating thirteen different species with knowledge of the substance. They were then able to synthesize a single molecule of Omega, which remained stable for one trillionth of a nanosecond. The resulting explosion destroyed 29 Borg ships and 600,000 Borg drones. The Borg revered Omega, which they called Particle 010, because they believed it existed in a state of near perfection. Due to this belief, all Borg were order to assimilate Omega at any cost. They were eventually able to build a harmonic resonance chamber that would theoretically stabilize the Omega Molecule.

Discovery by Starfleet
In the late 23rd century, a single molecule of Omega was synthesized by Doctor Ketteract, a Federation physicist on board the Lantaru sector research station. The molecule remained stable for only a fraction of a second before exploding. The energy released in the explosion destroyed the research station, killed all 127 scientists on board, and destroyed subspace through the Lantaur sector. The destruction of subspace made creating a stable warp field impossible, hampering rescue attempts. The accident was covered up and the impassibility blamed on natural phenomena. Soon after, Starfleet Command supressed all knowledge of Omega and instituted the Omega Directive, to which only starship captains and flag officers were given access. The Strategic Services Agency later gave access to Chief Intelligence Officers as well.

USS Voyager
"Omega destroys subspace, a chain reaction involving a handful of molecules could devastate subspace throughout an entire quadrant. If that were to happen, warp travel would become impossible. Spacefaring civilization as we know it would cease to exist. - Captain Janeway (Voy: "The Omega Directive")

A civilization in the Delta Quadrant was actually successful in synthesizing approximately 200 million Omega molecules in 2374. By using Omega's own resonance frequency, 1.68 terahertz, they were able to calibrate an effective containment field. However, an accident devastated their research facility, releasing the Omega molecules into space. Fortunately, the starship Voyager was able to neutralize the molecules before they did any additional damage to subspace.Seven of Nine adapted the Borg resonance chamber, changing it to emit an inverse frequency to dissolve Omega's interatomic bonds. Seconds before the chamber was jettisoned, Omega spontaneously stabilized and remained stable for over three seconds. After the chamber was jettisoned, Voyager destroyed the remaining Omega molecules with a gravimetric torpedo.