The EFS Nightmare (DD-921) was a heavily modified Archer-class destroyer, designed to be fast, have long range and require little support. The modular center cargo bay was used for a custom-built laboratory with the full Earth Federation research database, including the restricted files on Project Exo-Genesis and Project Vitek. It became the key vehicle for Project Nightmare. It was part of the second batch of 30 ships that was built with the improved sensor suite once the development problems were ironed out from the first iteration. The ship was destroyed during the 1st Civil War.