Alchemy had a lair in an abandoned subway station.
Alchemy was knelt down, seemingly contemplatively, when Magenta came in and told him that she felt Frankie battling against her. Alchemy told her to show her foster dad that Magenta's in control and that Frankie will then know it as well.
After the team came up with a plan, they came here and had Wally confront and distract Alchemy while they moved in. After having seemingly won, an earthquake erupted outside, and a ball of light entered the room, and freed Alchemy's followers and killed all the cops. He moved so fast that no one could see him except Barry, and told Barry that his name is Savitar and that he's the god of speed, before preparing to kill him.