Waypoint 531 is a star system in the Deep Periphery, approximately 150 light years coreward from Nueva Castile. It consists of a red giant sun and "The Brothers", four large asteroids in varying orbits around the star.
The system shows up in early stellar cartography thanks to the near endless colonial expansion in the days of the Terran Alliance. Entirely unremarkable otherwise, Waypoint 531 was where the THS Yosemite, a Terran Hegemony colony JumpShip searching for a new world to call home, crippled its jump drive in 2499. Stranded without hope of rescue, the ship's crew and passengers perished not long after arrival, a lost footnote in the history of the Terran Hegemony.
During the limited exploration efforts enacted by Clan Blood Spirit during the Golden Century, they discovered the system in 2880 but deemed it of little value. Appearing on Clan charts in the wake of this brief visit, Waypoint 351 was used as a rallying point and recharging stopover for occasional Bandit Caste raids of the nearby Nueva Castile worlds.
In the late 3060s, a Word of Blake Explorer Corps team arrived and verified that the system was empty; within two years they established a small space station around one of the asteroids. It boasted minimal defense systems and was slowly built up as a supply point for a planed Word of Blake attack against the Pentagon Worlds. However, the Word of Blake Jihad would ensure such a strike would never come to pass. After that conflict resulted in loss of contact between the Blakist forces within Nueva Castile space and Word's leadership in the distant Word of Blake Protectorate, in early 3073 a concerned Precentor Irene Gillick gathered up much of the Blakist personnel and material within Nueva Castile and linked up with the forces at Waypoint 531. At that time Waypoint 351 contained enough supplies of BattleMechs, ammunition and other military hardware to outfit an entire Division, but it unknown what Gillick intended to do with that hardware.
In July 3073 a Dark Caste flotilla led by The Jaguar and escorted by the Mako-class corvette Fuchida arrived at Waypoint 531 and was surprised at finding the Blakist JumpShips in the system. With the Bandit forces immediately attacking and gutting two Blakist JumpShips, with minimal Aerospace Fighter coverage and having nothing to counter even a partially functional WarShip, Precentor Gillick surrendered. The Jaguar traded the Blakist prisoners to the Tanites for food and supplies, and used the captured equipment for raids against Nueva Castile, the Hanseatic League, and several Clan worlds.
In November 3073 the Clan Goliath Scorpion Volga-class transport Andromeda arrived in the system with the Third Seeker Cluster on their way back to the Homeworlds from the former Rim Worlds Republic region of space. Seeing a seemingly derelict Mako-class Warship near an orbiting space station, the Seekers approached believing they had found a Star League cache. Though surprised when they were attacked by the Fuchida and a few DropShips and Fighters, the Scorpions quickly dispatched the bandits.
After inventorying their new conquest, Star Colonel Yeh of the Third Seekers left behind a Binary to guard their prize and returned to Roche. The system would later play an important role for the Scorpions. Upon reaching news of the discovery of the system, both Khan Ariel Suvorov and saKhan Connor Rood agreed they would ultimately be forced to evacuate the Homeworlds to survive, and made plans to invade and conquer Nueva Castile.
In 3074 saKhan Connor Rood was charged with leading a task force composed of Beta Galaxy, escorted by a trio of WarShips, the Congress-class frigate Bernlad, the McKenna-class battleship Lei Kung and the Potemkin-class cruiser Karttikeya, in a reconnaisance mission to Nueva Castile. Upon arriving at Waypoint 531 they found no sign of the Binary that was left behind. What was present was another WarShip—a battered Black Lion-class battlecruiser—with its crew trasferring the cache to its holds. The ID-codes revealed the ship to be the CSJ Streaking Mist, a former Clan Smoke Jaguar vessel. In the following battle, the Streaking Mist dealt significant damage to the Bernlad, then vanished taking half of the cache with it.
After the end of the Wars of Reaving the Scorpions strengthened their holdings in the system, using it as a base for further Deep Periphery exploration. When the Clan was Abjured in 3078 they began streaming supplies there, and managed to evacuate much of their assets. They regrouped and used Waypoint 531 as the base from which to launch the invasion and conquest of Nueva Castile.
- Wars of Reaving, p. 128, "Trials of Annhilation - Scorpion Gambit - Stellar System Waypoint 531"
- The Wars of Reaving, p. 129
- The Wars of Reaving, p. 157-158