The Broken Circle was a syndicate formed by disaffected former soldiers from the Federation and the Klingon Empire, who were veterans of the Federation-Klingon War of 2256–57. Following the end of the war, they took over the dilithium-rich planet of Cajitar IV.
Desiring a return to the exorbitant profits reaped by Cajitar IV's mining syndicate during the war, the Broken Circle plotted to reignite the conflict by launching a false flag attack on the Klingons. They secured the hulk of a NCC-1279-type Federation starship, NCC-1279, and secretly rebuilt it in a mined-out cavern using black market Federation technology.
In 2259, Lieutenant La'an Noonien-Singh discovered the Broken Circle's intentions while reuniting Oriana with her parents, and called the USS Enterprise for assistance. While administering aid to the miners, Doctor Joseph M'Benga and Nurse Christine Chapel were pressed into service by the syndicate. Taken aboard NCC-1279, they managed to escape their captors and modify the transponder to message the Enterprise to destroy the ship. From this, acting captain Spock surmised the syndicate's plan and destroyed NCC-1279 before it could fire on a Klingon cruiser. Spock then exposed the Broken Circle's activities to Klingon Captain D'Chok. (SNW: "The Broken Circle")