Dirgo was a humanoid male – of a species possessing a heavy brow, and a slightly wrinkled nose with a slightly bifurcated nasal tip – who served as the captain of the mining shuttle Nenebek during the 2360s.
His ship, which was in poor condition, crashed on Lambda Paz, a moon of Pentarus III. The moon was a desert, and his ship had no emergency food or water. They found shelter in a cave that contained a fountain of water, but were prevented from getting to it by a force field. Dirgo tried to shoot through it, but an energy sentry knocked him down and caused a rockslide, injuring Picard. Dirgo tried to use a phaser again, and he was enveloped in electrically-deposited selenium fibers by the energy sentry, killing him. (TNG: "Final Mission")