After delivering Cavador to Viktoria, Garrett steals a Servant mask to learn about a Mechanist technology called a "Cultivator". Meanwhile, Karras hides inside the Mechanist cathedral in preparation for his plan. Garrett and Viktoria learn that it is the Cultivators inside Servant masks which emit red vapor, or "rust gas". Karras had provided Servants to nobles with gardens in order to set off an apocalyptic chain reaction. Viktoria plans to lure the Servants into the hermetically sealed Mechanist cathedral before Karras activates their masks, but Garrett believes this to be too dangerous and leaves. Viktoria goes to the cathedral alone and dies while filling it with plants, and Garrett completes her plan, killing Karras in the rust gas. Afterward, Garrett is approached by Artemus, who explains that Karras' scheme and Viktoria's death had been prophesied. Garrett demands to know the rest of the Keepers' prophecies as the game ends.