The Perseus Arm is one of the spiral arms of the Milky Way Galaxy, situated between the Cygnus Arm and the Sagittarius Arm. It is likely located in the Alpha and/or Beta quadrants. During the Borg Invasion of 2381, the USS Aventine and USS Enterprise-E investigated a series of subspace tunnels centralized in the Azure Nebula. One of the tunnels exited the Aventine into the Delta Quadrant halfway between the Carina Arm and the Perseus Arm. (ST - Destiny novel: Mere Mortals)