Located within Section 31's Forward Operating Base in its data center, Control was Starfleet's threat-assessment system. Relying on artificial intelligence from the future that Starfleet had harnessed, they relied on it for recommendations regarding all critical strategic decisions. Only a Section 31 Admiral could interface with it directly. Admiral Patar, a logic extremist, was lobbying for Starfleet to turn all decisions over to Control before she was killed by it.
In an attempt to achieve consciousness, Control infiltrated Airiam's enhancements, forcing her to begin downloading the data Discovery had obtained from the sphere before it died, but when she realized what was happening, she convinced the crew to shoot her from an airlock so she couldn't be a danger to them.
Control then possessed Leland, the leader of Section 31, in an attempt to continue accessing the sphere data, which resulted in a battle between all of Section 31's ships and drones, the Discovery, and the Enterprise.