Angor returned to his rented lab in The Tributary.
Greya just proved to him that it was fairly easy for wizards to monitor his conversations and actions. To avoid trouble, Angor decided to finish Greya's request in The Tributary, which was located in another dimension.
Angor more or less had an idea about what type of illusion he should make before going to Sleepless City with Sunders. Greya only mentioned two things when she made this request. One, the illusion had to have the "atmosphere" of the Nightmare Realm, and secondly, it should look something new and creative.
Angor was mostly concerned about the second requirement. Earlier, he planned to create a "sandbox" world like the Witch's Town or Nether City while allowing Greya to explore the illusion on her own free will without following a fixed storyline.
But he just got another idea.