In 2258 the USS Discovery and USS Enterprise fought Control's Section 31 fleet at Xahea until Discovery could escape into the far future with the sphere data.
Control needed the sphere data held in Discovery's computer to complete its evolution, and the data could not be deleted. The crews of Discovery and the Enterprise decided the only safe choice was to take the ship beyond Control's reach by sending it through time, guided by Michael Burnham in a new Red Angel suit powered by a time crystal.
Control's ships, led by the Leland it had taken over, attacked while the crystal was charging. The two starships were joined by allies, including L'Rell's Klingons, a Kelpien fleet and the Xahean queen Po. Admiral Katrina Cornwell gave her life aboard the Enterprise, holding back a blast door to contain an unexploded torpedo.
Aboard Discovery, Philippa Georgiou and her allies trapped Leland in the spore chamber and destroyed him with magnetism, freezing Control's drones. Burnham opened a wormhole, and Discovery followed her into the future. Starfleet then recorded the ship as destroyed and ordered the survivors never to speak of it.