“It’s a bit complicated,” said James. “Hello, Magnus. It’s good to see you.”

“Last time I saw you, you were facedown in the Serpentine,” Magnus said cheerfully. “Now you’re fiddling with a Pyxis. I see you have decided to follow in the long Herondale tradition of poor decision-making.”

“So have I!” said Lucie, determined not to be left out.

“I came all the way from Jakarta to have a meeting with Tessa and Will about this whole daylight demon plague business,” Magnus said. “Yet when I knocked on the front door, no one answered. Thus I was forced to come in through the Sanctuary.”

“It’s odd they would have asked you to come here now,” said Thomas. “Everyone over eighteen is out searching for the demons responsible for the attacks.”

Magnus furrowed his brow. He lifted his hand to stare at the expensive-looking watch on his wrist and groaned. “It seems that I forgot to turn my watch backward and therefore have arrived six hours early. Bloody hell.”

Matthew looked delighted. “We could have tea. I am a true enthusiast of your work, Mr. Bane. Also, your personal style. Your waistcoats alone…”

“Matthew, do shut up,” said Thomas. “Mr. Bane doesn’t want to talk about waistcoats.”

“Untrue,” said Magnus. “I always want to talk about waistcoats. But I admit I’m more curious about this Pyxis.” He drew closer and poked at the box with his Malacca walking stick. “Am I correct in deducing that you opened the box on purpose and let a Palpis demon out?”

“Yes,” said James.

“… Why?” said Magnus.

“We need to be able to use the Pyxis,” Matthew burst out. “To trap a demon. So it had to be empty. We were just—clearing it out.”

James sighed. “Matthew, you would be a terrible spy. You might not break under torture, but you’d tell someone anything they wanted to know in exchange for a nice pair of trousers.”

“Oh, for goodness’ sake,” Cordelia said. She turned to Magnus. “You want this demon business over, right? You don’t want any more Shadowhunters to die?”

Magnus looked startled to be addressed so forcefully. “I am generally not on the side of murderous demons, no.”

“Then perhaps you could help us,” James said, and quickly outlined their plan, or at least as much of it as he could tell without breaking faith with Ragnor. Their belief that they were seeking a kind of demon that could only be trapped by a Pyxis. James’s vision of the shadow realm and reason to think that the demon would be on Tower Bridge. As he spoke, Magnus looked more and more curious. By the end of the story, Magnus had seated himself on the edge of the fountain, his long legs stretched out in front of him.