Talking Stone makes Celica visit the Demoness. She will instruct you to retrieve a Demonic Egg from the guild. She provides you with a Sleeping Vial. Event does not occur
If you are trying to play through the game using the manual, then this is a bad idea.
In Agranor's library, study game mechanics and explore the game world according to these mechanics. And if difficulties arise: the bartender and the fortune teller will help with a hint.
I myself first tried to count numbers and indicators. But then I noticed books in Agranor's library. They are small, but they explain how the game works.
After that it became much easier to play. Well, perhaps there is a routine here and there, but that’s something else.