“In order to activate the sigil, you’ll need to get to the square in the exact centre of the city. On your way you’ll be faced with two challenges. I don’t know what they are and I don’t know how to beat them. Once you get past them, you’ll face the Guardian in the final challenge. I’m assuming that one’s a brawl, which should make you happy. I know how you like to hit things.”

“One of my hobbies,” Skulduggery murmured.

Skulduggery continued on, while Fletcher followed Wreath to a hidden staircase that led up to a long room with an open balcony. Fletcher hurried over, stood with his hands on the cold stone, looking down at the city. He saw Skulduggery almost immediately, a lone figure moving in the stillness. More than that, though, he heard him. He heard every footstep. Somehow the acoustics of this huge chamber fed the sounds from the city up into the balcony.

Wreath reached out, and Fletcher realised there was glass in front of him. At least, he thought it was glass. A few swipes of Wreath’s hand and their view of Skulduggery was magnified.

“That’s pretty cool,” Fletcher said.

“Indeed it is,” said Wreath.

They followed Skulduggery’s progress for ten minutes. Shouted directions were not needed, as it turned out. Skulduggery was reading the air, somehow divining what path came to a dead end and what led on.

Then there was movement, and a shape emerged from the shadows.

“Who goes there?” the shape asked. The voice was male. Scottish. The viewing window showed a person in a black robe, wearing a porcelain mask.

Skulduggery stopped and observed the shape. “My name is Skulduggery Pleasant. I’m here to activate the Meryyn sigil. Do you mean to stop me?”

“No,” said the shape, and Fletcher realised that it wasn’t a mask he wore, but his actual face – porcelain and delicate and astonishingly creepy. “I am the Inquisitor. I mean only to test you. Whether or not I have to stop you will depend on the outcome.”

“What’s the test?”

“A simple one. A test of purity. You have no skin, I see. Nor blood nor organ.”

“Correct.”

“A curious creature. I know of some who would very much like to examine one such as you. Would you be willing to be examined?”

“Probably not.”

“A pity,” said the Inquisitor. “If you agreed to be examined, I could let you pass. I would deem that a worthy enough compromise.”

“I’m not here to compromise,” said Skulduggery. “I’m here to take the test and activate the sigil.”

“But the route I offer you is easier. All it would require is your consent to be examined. I assure you, it would take no longer than the life of a day.”

“I said no.”