The Orias system was a planetary system in Cardassian space with one uninhabited M-class planet – Orias III. In 2371, Starfleet Intelligence believed that the Cardassians were secretly building a fleet in the Orias system, without the knowledge of the Central Command. The Maquis feared that this build-up was a prelude to a new offensive in the Demilitarized Zone, and so Thomas Riker stole the USS Defiant to investigate. He was prevented from entering the system by several Keldon-class warships fielded by the Obsidian Order, though he did provide the Central Command with scans of the system in exchange for clemency. (DS9: "Defiant")