(coexisting on another dimensional plane)
When Voq's encampment on Harlak was discovered by Imperial Intelligence, the ISS Shenzhou was dispatched to destroy the base and all rebels within it. Unknown to Starfleet, however, the Shenzhou's captain had been replaced by her Federation doppelganger, Michael Burnham, who instead chose to warn Voq and ask him how he had achieved cooperation between Klingons and other species.
After answering her questions, Voq was attacked by Lieutenant Ash Tyler, whose true personality as Voq's counterpart had reacted violently to Voq's willingness to work with aliens. Tyler was quickly defeated and allowed to return to the Shenzhou with Burnham.
Voq and his followers began evacuating but were interrupted by Emperor Philippa Georgiou, who arrived in the ISS Charon and bombarded Harlak's surface, destroying the base and much of the continent. (DIS: "The Wolf Inside")