The study was covered in books and had two comfortable chairs in front of a roaring fire. A man was sitting in one of them with a book on his lap and was snoring gently. There was a knock on the door and he sprang up. He opened the door and peered out to see Sir John Jennings in the street.

“Professor Herringbone-Stove?” asked Sir John.

“Who is enquiring?” said the man.

“It’s Sir John Jennings,” said Sir John. “I believe I have an appointment?”

“Ah, yes!” exclaimed Herringbone-Stove. “Come in!”

“Professor Herringbone-Stove?”

Sir John walked into the room and the professor glanced up and down the street before closing the door. He indicated the unoccupied chair to Sir John, who sat down.

“Just out of interest,” said Sir John, “which university are you attached to at the moment.”

“Well I’m at…” started Herringbone-Stove, before commencing a long coughing fit, during which he sat down opposite Sir John. The professor leaned forward and arched his fingers and his eyebrows.

“So,” Herringbone-Stove said, “ you wish to know about … mesmerism!”

“Indeed,” said Sir John enthusiastically. Herringbone-Stove looked a little disappointed at this response. “I have a case at the very moment that I feel you may help me with. You see it concerns a woman who I believe is under the thrall of a mesmerist. I believe him to be working to a most diabolical purpose.”

“Strong words sir and easily misused,” said Herringbone-Stove. “Some of my lectures have been described as diabolical.”

“I’m sure they have,” said Sir John. “But the fact remains, she is catatonic, the doctors can do nothing, and her last known contact … was a mesmerist.”

“Fascinating,” said Herringbone-Stove, “but I still doubt your theory. To be able to carry out such an feat, a man would need tremendous mesmeric powers, even with the help of something like the Sphere of Lethe.”

“The Sphere of Lethe?” said Sir John.

“It was an artefact possessed by Mesmer himself, that purportedly amplifies mesmeric power,” said Herringbone-Stove.

“Good Lord! Named for the river, I suppose,” said Sir John.

“The river?” said Herringbone-Stove.

“The River Lethe. One of the rivers of the Greek underworld.”

“Let me just write something down unconnected to our conversation,” said Herringbone-Stove. He started to write on a pad and said “riv – er” under his breath.

“So how does the Sphere work?” asked Sir John.

“Ah! Well, I have a theory,” started Herringbone-Stove, “that it works by enhancing aural electricity. You see, I firmly believe that mesmerists have long misunderstood their own power. They call their powers animal magnetism, and Mesmer himself believed it was identical to actual magnetism. This is palpable nonsense. The power that mesmerists use is clearly based in electricity, produced by the pineal gland, directed at the target and amplified by auditory excitation. The sphere, I believe, further increases this auditory excitation, thus enhancing the mesmerist’s power.”

“Fascinating,” said Sir John. “But how would this auditory excitation work? And how might one defend against it?”

“You, sir, are as ugly as a baboon!” shouted Herringbone-Stove.

“I beg your pardon!” said Sir John turning red.

“You see, that is an example of auditory enhancement of mesmeric electricity. I fired my pineal gland at you and enhanced that with the power of my voice. It provoked in you a marked emotional response, namely rage. That is the power of the mesmerist.”

“I see,” said Sir John, still shaking a little.

“I posit that there are two forms of defense against this. The first is that one must block up the ears to ensure they do not hear the voice of the mesmerist. The second is to direct a beam of electricity back at the mesmerist’s pineal gland. Sadly, I am no engineer, but I have no doubt that in this modern age a suitable device could be made.”

“So where is this sphere?” asked Sir John.

“Well, until recently it was held in the British Museum in London in a display of Mesmer’s effects. But I believe last year the whole collection was sold to a local artistic foundation. Around March, I think. They were displayed here in Manchester briefly. But really, Sir John, it would take a master mesmerist to use this device.”

“Professor Herringbone-Stove, my client is connected with an artistic foundation and last April was when she was struck down. I now wonder whether this Sphere was used to do that.”

“Good Lord!” said Herringbone-Stove, leaning forward and lowering his voice. “But there is only one man I can think of so powerful and malignant. Only one who would dare to defy the laws of nature in such a way. Only one who might sink to such depravity!”

“Who, man? Tell me!” said Sir John, leaning forward too.

Professor Herringbone-Stove moved as close to Sir John as he could. His face was pale and his voice barely a whisper.

“His name sir … is Arthur Clackprattle.”

The Mancunian Mesmerist: Chapter 10