“I could give you a list of names – but it would be a short list, made even shorter by events over the last few years. Actually, I think your next port of call is a book, not a person. The Hessian Grimoire is a collection of, essentially, theories about the next stages of magic. Where we can go from here, how we can expand our knowledge, the ways in which we can use what we know to delve deeper into the source of all magic. I don’t know who is currently in possession of the book, unfortunately, but if you can find it, I think it could help you.”

“The Hessian Grimoire,” Darquesse said, nodding. “OK then, sounds good. And after that? The list of names you were going to give me?”

Tarry raised his chin and moved his head from side to side, acknowledging the request, but see-sawing between options. “There are two or three people left alive who could help you. Really, the person who could have helped you the most would have been Walden D’Essai.”

“Argeddion.”

Tarry nodded. “His work was just … it was far beyond any of his contemporaries. I never liked the man, I was always far too jealous of his accomplishments. That’s something I could never have admitted without this Remnant inside me, by the way.” He chuckled, and didn’t seem to notice when Darquesse didn’t join in. “But his mind was an astonishing thing. His work, his research … Even the questions he posed in his field outshone the answers I got in mine. If you truly wanted to master this thing called magic, if you truly wanted to touch infinity … I would have said talk to D’Essai. Talk to Argeddion. But, of course, now it’s too late.”

“Argeddion is alive,” said Darquesse.

Tarry frowned. “No. He’s dead. Skulduggery Pleasant killed him when—”

Darquesse spoke over him, her words calm. “Officially, Argeddion died following the confrontation with those super-powered hooligans he’d created. Skulduggery finished him off. That’s the story that was circulated.”

Tarry sat forward. “It’s a lie?”

“They couldn’t kill him,” Darquesse said. “They didn’t know how. So they rewrote his personality, convinced him he was normal, and hid him away. Even I don’t know where he is now.”

Tarry was quiet for a moment. “The Hessian Grimoire,” he said. “That should help you find him.”

“How?”

“You have a deep understanding of energy, Darquesse. Your understanding might even surpass my own.”

“Oh,” said Darquesse, “it does.”

A faint flicker of irritation crossed Tarry’s features. Sanguine noticed it. And if Sanguine noticed it, then Darquesse certainly did. That faint flicker of irritation had most likely just signed Mr Tarry’s death warrant.