Silent Rift
The Silent Rift is an area of space in the Lantaru Sector where subspace has been permanently damaged. Unknown to everyone except Starfleet Captains and Admirals, the reason it was damaged was a failed experiment by Federation scientists. In 2269, they were experimented on the Omega particle when the experiment failed, destroying most of the sector subspace. After that catastrophe, Starfleet created the Omega Directive, and created the fall story that it was a natural phenomena.
Since, warp travel has become impossible in the sector, causing the population leaving there to become isolated due to increased time to travel through the sectors.
Recently, new ways has been found to allow to travel faster within the sector. From the latest report, it has created some instability in the sector. This lead Starfleet to assign on stardate 2414.11.07, the USS Starfire to investigate.