Helen the magician reached behind her back with both hands and unsheathed two swords, long and thin and bright as if they were rays of light cast on water.

“Do you think you’ll even be a challenge, demon?”

“I’ll do my best,” said Nick, and drew his own sword.

It was his favorite sword, the one Alan had given him at the Goblin Market. Mae remembered it as she remembered everything about the Market night. It looked like nothing compared to Helen’s swords, which caught the fluorescent lights set into the steel of the bridge, the glow of the city spread out along the river, and turned all the lights into magic. Every time she moved her swords, they painted vivid trails of gold dust against the night.

They walked around each other in a slow, tight circle, watching the way their opponent moved.

“Two swords,” Nick commented. “Trying a bit too hard?”

“Maybe you’re not trying hard enough,” Helen said. “If all you can handle is one.”

Nick circled around, and Mae caught the flash of his savage grin.

“Oh, I think all you need is one. If you use it just right.”

Their swords met with a sudden ring, like the peal of a bell. Nick’s sword hit the spot where Helen’s blades met, crossed before her. She smiled, face framed by sharp steel, and Nick disengaged. Helen went low, snake-fast, and struck out at knee height. Her intention was so clear that for an instant Mae saw what Helen wanted as if she’d already made it happen: Nick’s legs scythed out from under him, having him bleeding and helpless for her final strike.

Mae moved forward and was pulled up short by the hard bite of Alan’s fingers into her arm. He pulled her back, tight against his chest, and said into her ear, “Don’t move.”

She didn’t move. She figured he must want comfort, though she wouldn’t have thought he’d seek it by grabbing someone hard enough to bruise.

It didn’t matter for long. They both had to keep watching Nick.

He jumped to avoid Helen’s swords and landed crouched, the aluminum deck reverberating under his feet.

Helen thrust, one sword cutting a golden wound in the night sky. Nick had to slam against the railing to avoid the blow, and then she was sweeping with the sword in her left hand to run him through where he stood.

Nick vaulted over the rail and onto the fragile cables on the side of the bridge, dancing backward on them as if they weren’t impossibly dangerous monkey bars suspended above murky waters.

Helen sliced out at him in a double stroke that could have beheaded him if she’d had more reach. He leaned backward, away from the swords, and for a moment either he or the bridge swayed and Mae shut her eyes, convinced he was going to fall.

“Stop playing around,” Helen snapped. “Let’s cut to the chase.”

Mae opened her eyes and saw Nick crouched like a huge cat on the end of a cable, sword washed in city lights and turned into a sweep of cool silver.

“This is the chase,” said Nick. “Cutting comes later.”

He grabbed the steel rail in one hand, and his arm tensed: the only sign before he threw himself over it, landing rolling on the deck and turning the roll into a stand almost too swiftly to see.

Not too swiftly for Helen. She swung, and Nick swerved. Directly into the path of her second blade, which slid between his ribs.

It was so simple and done with so little fuss that for a moment Mae forgot to feel alarmed. Then she heard the sound Alan made in the back of his throat, scraping and pained, as if he was the one who’d been stabbed. She saw the bloodstain spread slow and red across the white of Nick’s shirt.

Before Helen could draw her sword out, Nick attacked her unprotected side, his sword slicing in. She dived away, her shirt torn and bloody, pulling her sword out of Nick’s chest as she went.

Nick clenched his free hand into a fist and pressed it hard against the bloodstain, then swung in while Helen was still off balance. She fumbled the blade that was still dark and slick with Nick’s blood, and Nick struck her wrist hard with his sword. She gave a hoarse cry and dropped it.

“Now we’re even,” said Nick.

“We’re not even,” Helen said. “I was using magic and my swords before you were ever born.”

“I was killing long before you were born,” Nick told her, suddenly soft, as if struck by a pleasant memory. “I’ll be killing long after you’re dust.”

“You sure about that?” Helen said. “I’m not.”

Their swords met again, once, twice, three times in a ringing flurry of silver and gold, sparks flying into the darkness. Nick pressed in, and even Mae could see that wasn’t good for Helen: With their blades locked, Nick had the advantage of height and weight. He could drive her down.

Mae’s leaping heart went still and cold as a stone in her chest when Helen’s remaining sword flared into sudden vibrant life, humming and glowing with the white intensity of the sun.

Nick’s sword, locked tight with the magician’s, broke in two against it. The blade went clattering to the deck, and Nick was left standing there holding the hilt, a broken shard of steel still attached to it. It looked pathetic, especially next to Helen’s shimmering weapon.

Nick tossed it up into the air, caught it by the shard, and when Helen’s eyes followed the movement for an instant he moved past her guard and hit her hard in the nose with the hilt, then dropped it and punched her in the stomach. When she doubled over, he lunged away from her and across the bridge to seize the other sword, the one she’d dropped.

Helen looked up, blood streaming down her face, as he bore down on her.

She parried Nick’s blow and then struck. The sword Nick held was dimmed, ordinary again, while the one she still held was ferociously bright. It seemed to leap in her hands, and Mae clenched her fists at every blow, the ring of blades meeting turning into a murderous little song. Nick’s and Helen’s feet were moving together, back and forth, like a dance.

Nick was bleeding too much. There was a scarlet trail leading down from the wound his fist was still clenched over, and from the end of his shirt blood was dripping, forming a dark pattern on the bridge.

“I’m sure,” Nick said. Their blades flashed and rang, again and again, faster and faster, until all Mae could make out was a metallic blur and Helen’s white face. “And I’m sure of something else. You should’ve spent your time learning to use these swords, not magic them.”

The humming of Helen’s sword was more like shrieking now, a thin sound with steel and rage behind it. She went in again, wilder and sloppier, going for the kill. That bright sword kept coming within inches of Nick’s heart, his throat, his ribs. She scored another cut on the outside of his thigh.

Nick kept his blows steady and controlled, making every one count. Helen feinted to his wounded side, and he faltered. She dived in to exploit the moment of weakness, close to his body, and Nick struck her a blow that forced her arm up.

Her sword went flying into the air, sketching a golden arc against the night sky. Then it fell, all brightness lost, and was swallowed by the dark waters of the Thames.

Nick kicked Helen’s kneecaps, sending her legs out from under her. She tumbled down to her knees before him on the bridge, and he rested his sword lightly against her neck.

“Finish it,” Helen ground out, without lifting her bowed blond head.

All Mae could see was his back, his black head bent to survey his kill. He looked huge and menacing suddenly, now that the woman was on her knees. Now that she was helpless.

“No,” Nick said at last.

Helen did look up then. “Why not?”

“I don’t want to,” he said calmly. “I want you to go home, magician, and practice the sword without using magic. I want you to get really good. And then I want to fight you again.”

His voice changed a little on that last line, dark and anticipatory. Helen smiled.

“You’ve got yourself a date, demon.”

Nick strode forward to where the Aventurine Circle stood, transfixed and appalled.

Celeste Drake looked as if she might be considering taking some action as a demon advanced on her with a blade in hand.

“He won his prize,” Helen called back sharply over her shoulder.

Nick kept walking, swinging his sword in what seemed to be an idle manner. Celeste’s eyes followed it. Her free hand glowed a little, magic building hot in the center of her palm, and her other hand tightened on Jamie’s silver chain. Jamie wasn’t fighting anymore, but he was standing as far away from her as he could, the line of magic held taut between them.

“My prize,” Nick repeated. “You don’t have any slightly more impressive prizes on offer? Yeah, I thought not.”

Jamie looked indignant.

Nick said, “You are so much more trouble than you’re worth,” and brought his sword down viciously hard, cutting the magical tie between Jamie and Celeste Drake in two.

Jamie launched himself bodily away from the magicians and at Nick, almost knocking into him. Mae’s relief at seeing that silver cord severed was cut short when she realized why Jamie, who usually kept his distance from Nick, was pressed up against him with a hand over his. Jamie was trying to staunch the bleeding.

It was hard to tell when Nick was pale, but his lips were leached of all color, white and set in a thin line.

“Come back whenever you need to, Jamie,” Celeste said gently. “Demons always turn against you in the end.”

Nick turned his back without a word. Jamie went with him.

“C’mon,” Alan breathed, and Mae turned in time to see him slip a gun into the waistband of his jeans.

Alan hadn’t pulled her back and held her bruisingly hard for comfort. He’d positioned her deliberately, had her exactly where he wanted her, so she stood between him and the magicians. So her body blocked their view of his gun.

Jamie was on one side of Nick and Alan on the other as they went down one of the twin ramps, and Nick had relaxed enough to sag against his brother.

It occurred to Mae that Nick hadn’t pushed Jamie away when he flew to him because Jamie was helping him stand up.

“Jamie, let me.”

“No,” Jamie told her. “I’ve got him.”

“I want my sword,” Nick said without looking over his shoulder.

“Right,” said Mae, and ran back.

The Aventurine Circle were in the process of leaving the bridge, going north toward St. Paul’s, which was white as carved bone gleaming in the city lights. Helen was holding her side, one of the male magicians hanging solicitously around her. Celeste was still facing south, and she saw Mae coming.

Celeste’s eyes narrowed as she watched Mae kneel down on the deck and reach for the broken sword.

“The demon’s errand girl, are you?”

“The magician’s sister,” Mae corrected.

Celeste’s eyelashes swept down, modest as a lady hiding behind her fan. The china doll face was restored, a perfect mask now that the incongruously intelligent eyes were hidden.

“When you’re ready to be your own woman,” she said, “come find me.”

She reminded Mae of a different magician suddenly. For an instant the cold bridge at night slipped away and she saw Olivia again, Nick’s mother, with her midnight hair and her mad eyes, leaning close to whisper.

It’s probably best to change the world yourself, she’d said.

Before she died.

When Mae focused on Celeste again, the woman had already turned, fragile shoulders hunched slightly against the cold, the lights of riverside London blurring the gold of her hair and the white wool of her dress into one iridescent shape walking away. Mae had no chance to ask her what she’d meant.

She cut her hand picking up the broken blade that was half of Nick’s sword, and felt hot blood well up in the chilled hollow of her palm. She closed her fingers over blood and blade and ran to catch up with the others.