“You tell me,” said Beetle.

Marcellus said nothing.

Beetle continued. “Now, if we place the tracing over the Vent diagram, like so . . . we can see that each red dot is on top of the end of a line on the diagram.”

“So it is,” murmured Marcellus. “How very interesting.”

“And I presume each line ending is a Vent.”

Marcellus shrugged. “Whatever a Vent is.”

Beetle knew he had to keep cool, but it was not easy. Fighting to keep any vestige of irritation out of his voice, he continued, “I—we—believe that the note is indeed from you and we believe that you wrote it to Julius Pike. FYI is, as I am sure you do actually remember, archaic shorthand for ‘For Your Information.’ Marcia and I are convinced that there is a connection between these puddles and the Fyre in the Great Chamber of Alchemie. We would like an explanation as to why the puddles occurred before the Fyre has even been lit. Before, in fact, the Chamber was opened.”

For a few seconds, Beetle thought he had done it.

Marcellus sighed and said, “Indeed, there is a connection. Perhaps I may demonstrate?”

Beetle nodded.

Marcellus took a pen and proceeded to add a series of thick black crosses to the red dots on Beetle’s Castle plan. He then joined them up so that they formed a wavy line that meandered from the South Gate by the river to the Wizard Tower.

“You will find that all these places will have melting snow,” he said, looking at Beetle over the top of his spectacles. “You will also see that by no means all these spots have a—what do you call it—a Vent beneath them as shown on the diagram. It is an unfortunate coincidence that the ones you have found just happen to be above one of these Vent things. Whatever they may be.” He shrugged. “Coincidences happen.”

“Coincidences?”

Marcellus took off his spectacles and looked up. “Dragon blood.”

“What?”

“Dragon blood. After his fight with the Darke dragon, Spit Fyre left a trail of blood from the South Gate to the Wizard Tower. Each red dot, and now each cross, marks a spot of blood. You will find the snow has also melted at every cross I have drawn. I agree there is a link between the opening of the Chamber and the melting snow, but only insofar as that the flight made by Spit Fyre led to us being in the happy position of being able to do this at all.” Marcellus looked at Marcia. “No doubt you know all about the eternal heat of dragon blood?”

Marcia was not sure she did, but she was not going to give Marcellus the satisfaction of admitting it. “Of course I do,” she snapped.

Marcellus knew the interview was at an end. He took off his spectacles and put them back in their red velvet case. “Dragon blood is a wonderful thing, but it does have a tendency to lead to puddles in snow, which is most annoying for those who fall into them. I suppose your shoes were ruined, Marcia?”

“How did you know I—”

Marcellus stood up. He had won and he wanted to get out of Marcia’s study as soon as possible. “Now, if you will excuse me, I have important work to continue. I hope next time we meet it will be to do the job that we all wish to do—DeNature the Two-Faced Ring.”

Marcia opened the study door. “Yes, indeed.” She took a deep breath and said, “I apologize for interrupting your work, Marcellus. I’ll see you out.”

Beetle sat down with a sigh. Quietly, he put the Vent diagram and his tracing, now covered with taunting black crosses, back in his folder. He had made his first mistake as Chief Hermetic Scribe. It was not a good feeling.

Marcia returned without Marcellus. Beetle leaped to his feet. “Marcia, I am so sorry.”

“Nothing to be sorry about, Beetle,” said Marcia. “It’s all for the best. Marcellus knows we have our eye on him now. Please do not let this put you off. You must let me know about anything else suspicious—anything at all.”

Beetle felt very relieved. “Yes. Yes, of course I will. I will check out all the crosses he made.”

“Thank you, Beetle. Now I think we have both earned a strong cup of coffee.”

By the time Marcia escorted Beetle down the stairs he felt a little less embarrassed about the interview with Marcellus. As they spiraled down into the vaulted space of the Great Hall, Beetle saw that something had caught Marcia’s attention: Milo Banda was coming out of the duty Wizard’s cupboard.

Beetle saw Milo catch sight of Marcia and stop dead. Milo dithered. It seemed to Beetle that Milo wanted to skip back into the cupboard but was unsure whether Marcia had seen him. Marcia decided it for him. She jumped from the stairs and set off across the Great Hall at top speed. Beetle kept a tactful distance—something was going on, but he wasn’t sure what.