The story for this map is that a civilian research vessel is found abandoned in deep space after an attack by the Kharaa. The marines are sent in to take control of the vessel before the aliens can establish a strong presence which will result in the loss of the ship and the valuable research data onboard.
The map itself is not the entire ship, but rather an isolated section of it where the Kharaa are active. The marines will start from the hangar of their command cruiser, which is docked with the research vessel.
Derelict uses mostly textures from the ns, ns2, and eon wads, and a few I made myself. The theme of the map is inspired by System Shock 2.