Wizards often encountered situations unsuitable for Apparition. One was when traveling with magical creatures; Scamander had taken Muggle transportation when he went to New York.
Another was when traveling with infants. To take Harry away from Godric's Hollow, they had gone to great lengths in the end, with Hagrid riding Sirius's flying motorcycle to bring Harry to Petunia's home.
It was not absolutely forbidden. Augusta had Apparated with Neville while he was still asleep, after Frank and Alice had been abducted by Bella and the Death Eaters who broke into their home.
"Why are you here?" Georgiana asked, because Julian Ouvrard had somehow come to Murat's house.
"How was the party?" Julian, sitting on the sofa, woke from his sleep and asked groggily.
"I told you to go back and rest," Georgiana said.
Rubbing his eyes, Julian asked, "Have you ever heard of the Eleusinian Mysteries?"
The very word "mysteries" gave her a bad feeling.
"They worship Demeter and Persephone," Julian said.
"Oh." She said rather innocently, "That sounds nice, but..."
She stopped there.
"If it were merely a ritual honoring the goddess of the harvest, I would not have come here in the middle of the night," Julian said. "They guard the secrets of the rites. No one knows the exact nature of their doctrines or ceremonies. What did you do there?"
"Why are you asking me?"
"I thought you would be accepted," Julian said.
Georgiana's memory stopped after she drank a glass of water...
Caroline could not drink alcohol either, and she was pregnant now. Had Denon drunk any water?
If they had all drunk it, and then all slept so deeply in the carriage, it might not have been caused by exhaustion.
"Do you remember what happened?" Julian asked gravely.
"I don't know why, but I kept