The Syndicate is a criminal organization that has a presence through out the Red Rising universe.
In the years before the Rising, they were center of power in Lost City on Luna, and were used by Octavia au Lune to advance her political interests.
Prior to the Rising, leadership of the Syndicate was a Triumvirate comprised of three members of a single crime family - one of whom was a woman named Vebonna - handpicked by the Sovereign herself for off-the-record tasks such as assassinations, rigging appointments, and engineering workers' strings in the domains of ArchGovernors who were inconvenient to her interests.
After the Solar Republic took control of Luna, Lilath au Faran reorganized the Syndicate into a hierarchical system with herself at the top as Queen, with those titled as Dukes being her group of assassins, one of them being the Duke of Hands. Enforcers in the Syndicate are referred to as Thorns.