An Orion-run enclave on the Klingon homeworld, built above dormant volcanic shafts, where the Discovery landing party goes in 2257 to plant what proves to be a planet-killing bomb.
The Orion embassy outpost is a settlement on Qo'noS seen in the first-season finale of Discovery, Will You Take My Hand?. Standing on land granted to the Orions, it is a crowded quarter of markets, gambling dens and pleasure houses, and one of the few places on the planet where outsiders can pass unnoticed.
The mirror-universe Philippa Georgiou, posing as her dead counterpart, leads Burnham, Tyler and Tilly there to find a shrine that gives access to the volcanic system below, supposedly to release a mapping drone. While the others gather information, Tilly discovers that the device she is carrying is a hydro bomb able to devastate the planet.
Burnham confronts Georgiou at the shrine and refuses to let Starfleet commit genocide. The detonator is handed instead to L'Rell, who uses the threat to unite the Klingon houses and end the war.