“Dux omnium homicidarum,” Reynevan confirmed pensively. “Also Mors per ferro. Those are snatches of the spells used when making it. Which is why Guido Bonatti in his writings uses the name ‘Perferro,’ which is also the name given in the Picatrix… In the Latin translation, because in the original it is khadhulu ahmar al-hajja, which means… I don’t recall what it means—”

“Never mind,” Horn interjected, “for I’m not interested. Reynevan, O venerable mage, so you thus confirm such a poison exists? And works exactly as just described?”

“I confirm what is written in certain sources,” said Reynevan, calming down and looking Schilling in the eyes, “but I shall not pass over what is written elsewhere. According to which the so-called Black Tincture is necessary to make Perferro—”

“Indeed, indeed, you are quite right, M’Lord Bielau,” Schilling hurriedly confirmed. “I heard Grellenort and Skirfir talking about it.”

“The legendary Black Tincture,” Reynevan continued, without lowering his eyes, “can only be obtained by transmuting a metal called chalybs alumen, which is ruled by the Eighth Planet. The problem, though, is that according to many scholars that metal only exists in legend. And one need not be a scholar to know that there are only seven planets—”

“There are eight planets,” the renegade swiftly countered. “I also learned that by eavesdropping. The eighth planet is called Poseidonos, and Grellenort is said to know of its existence from the Devil himself—”

“Let’s leave the Devil out of it for now,” Horn again interrupted. “And Ptolemy. Don’t get out of line, Schilling. I’m doing the interrogating, you’re being interrogated. And a moment ago Messer Reynevan quoted authorities that appear to somewhat refute what you are testifying. Authorities that do not lend credence to your testimony. That reject them. I warn you: telling me fairy tales may have nasty consequences for you.”

“M’Lord Horn.” Bruno Schilling immediately rid himself of obsequiousness. “I don’t give a fig for authorities and Ptolemy can count as many planets as he wants. But I tell you that I seized tramps, beggars and other wanderers from highways and delivered them to Sensenberg for Grellenort and Skirfir’s experiments. I saw them administering poison to them, and afterwards cutting them with iron. I saw with my own eyes the effect iron had on the action of the poison—”

“And how did the poison act?” interrupted Reynevan. “What were the symptoms?”

“The thing is, there were various ones. It’s a merit of that poison that it’s difficult to identify on the basis of symptoms: they are deceptive. Before they died, some of the victims thrashed around, others trembled, others cried that their heads and guts were burning and died so contorted that shivers ran down your spine at the sight. While others simply fell asleep and died in their sleep. With smiles on their faces.”

Horn shot a telling glance at Reynevan, to stop him from reacting.