Cordelia turned to realize a faerie woman with tumbling blue and green hair was also in the room. She was standing in an alcove, partially hidden: before her was a sideboard where she was mixing drinks. Her hands waved in midair like fronds in water, unstoppering decanters and crystal vials full of red liquid, and busily pouring them into a variety of goblets and flutes.

Cordelia’s eyes narrowed.

“Just ready, darling!” Arabella said, and walked over to distribute drinks. Matthew accepted a drink with alacrity. Cordelia noticed that Arabella walked with a rocking, unsteady gait, as if she were a sailor unaccustomed to treading on the land.

When Arabella gave Anna her drink, Anna pulled Arabella into her lap. Arabella giggled, kicking up her French heels. Her legs were shockingly bare, and covered in a faint iridescent pattern of scales. They flashed in the golden light like a rainbow.

A mermaid. So this was Hypatia’s “friend from the seaside.” They were a type of faerie rarely seen out of water, since their human legs caused them pain to walk on.

Arabella noticed Cordelia’s gaze and shrugged, shoulders moving fluidly beneath her heavy masses of blue and green hair. “I have not been on land for many years. The last time I visited this ugly city, the Downworlders and Shadowhunters were trying to form the Accords. I was not much impressed with Nephilim then, and I have not been fond of Shadowhunters since. Still, exceptions can be made.”

Before the Accords were formed. This woman had not been on the land for more than thirty years.

Arabella leaned into Anna as she spoke, and Anna’s scarred fingers drifted nimbly through the waves of the mermaid’s hair. Tiny fish, small as sparks from a fire and bright blue, stirred when disturbed and leaped from strand to strand, chasing Anna’s movements.

“My lovely, your hair is like a beautiful stream,” murmured Anna. “Because there are fish in it.”

Apparently Anna could seduce multiple people in one evening. Arabella blushed and bounced up to gather more drinks from the sideboard.

“We know why Anna brought you, Matthew,” said Malcolm. “You are amusing. But is there a reason this young Carstairs girl is accompanying you tonight?”

“Because we need your help,” said Cordelia.

Everyone in the room laughed. Malcolm smiled and raised his empty glass to Cordelia as if she had made a particularly good joke; Arabella was still at the sideboard, sprinkling flowers into two flutes of wine and humming.

Anna and Matthew looked pained.

“Magnus Bane would help them,” said Hypatia, the stars in her eyes sparkling. “That is why they have come. Magnus has made them believe a warlock will always help them.”

“Magnus is not here,” said Malcolm. His gaze was distant. “I bear you no ill will, child, but I loved a Shadowhunter once and it brought me only sorrow.”

“She became an Iron Sister, and broke his heart,” said Hypatia.