The 3189 collapse of the Emerald Chain, the Orion-Andorian crime syndicate, after its leader Osyraa seized Discovery and was killed by Michael Burnham.
After the Burn the Emerald Chain, a syndicate of Orions and Andorians, became one of the strongest powers in the region, controlling dilithium supplies and using slave labor. Its leader Osyraa saw the USS Discovery and its spore drive as the key to dominance.
In 3189 Osyraa seized Discovery near the Verubin Nebula. She used it to slip through the defenses of Federation Headquarters and offered Admiral Vance a peace treaty. Vance said Osyraa would first have to stand trial for her crimes, which she refused. She then fought her way out of the station.
Michael Burnham had reached the ship through the couriers' transwarp network and worked her way through it in secret. She killed Osyraa in the data core and took Discovery back. Without its leader the Emerald Chain soon collapsed, and planets that had lived under its power began to rejoin the Federation. Burnham was promoted to captain of Discovery.