They went around the pedestal bearing its sculpture of angels watching human misery, to the other side.

The Aventurine Circle stood in a group at the foot of the Monument.

Sizing up the enemy, Sin saw signs of dissension in the ranks. About half the Circle was there, and about half of those present were wearing the Aventurine Circle’s usual pale clothes. The other half were wearing ordinary dark or colorful clothes, and nobody was standing very close to one another, shoulder to shoulder as they should have with companions they trusted.

Helen the swordswoman was wearing white and had an air very similar to Nick’s about her.

Gerald was wearing clothes that were a combination of both light and dark, and his mood seemed to be shifting even as he stood there. Looking at him made Sin think of Matthias the piper: It came as another shock to realize that Gerald was very young as well.

Celeste had threatened him into joining her Circle, and now she was dead and he was leader of a Circle that barely knew him, that could hardly be expected to respect him. And he had lost Celeste’s pearl, not only a powerful magical object but the leader’s token of power in the Circle.

As they drew closer, Sin saw that Gerald was toying with the ring on his left hand, an obvious tell of discomfort.

An uncertain leader could be unpredictable. Gerald had invented the mark that delivered Alan into his hands. He was too clever and he had too much power over Nick: If he was feeling backed into a corner, he could be even more dangerous.

Sin noticed where Nick’s attention was fixed. He did not even seem aware Gerald existed. He was staring, murderous intent clear in every line of his body, at Seb.

His look seemed to clear a space around Seb, the other magicians unobtrusively drawing away. Seb stood on the gray cobbles, looking very alone.

He’d been looking as unsettled as Gerald, but strangely, Nick’s cold stare seemed to calm him. He squared his shoulders and glared back at Nick as if he would have a chance fighting him. There was hectic color in his face now, as if he had a fever, and a reckless glint in his green eyes.

The glint died and his eyes went flat as Gerald said, “Mae, always a pleasure. Come to make a trade?”

“That depends,” Mae said. “I’d like to know what this thing I’m trading the pearl for is. The one I’m supposed to find so interesting.”

Gerald smiled at her, though the smile was strained at the edges. “Well, here’s the thing,” he said. “If I thought Nick had the pearl, I would have just ordered him to hand it over. I thought it might be Seb, who is coward enough to grab at anything that looks like leverage, but I offered Seb the same trade as I’m going to offer you. I really think he would have taken it, if he’d had the pearl.”

The glance he cast Seb was dismissive. Seb shot back a look of such open loathing Sin was shocked: No magician was going to survive who displayed such hostility to his leader.

“I don’t have it,” Seb ground out.

“I believe you, Sebastian,” Gerald replied lightly. “I think Mae here has it. And she has a weakness.”

Gerald gave a smile: The corner of his mouth twisted as if he wanted to rip the smile off his own face.

“Everyone has a weakness,” he continued. “Either you destroy your own weakness, or people use it against you. I think this qualifies as me doing both.”

Gerald turned abruptly away from them, bowing his head, and made a swift gesture.

Laura and another magician, both in dark clothes, stepped apart.

Jamie was crouching at the base of the Monument, back to the white fence surrounding it. He was in chains.

Sin had known he would pay for defending Nick. She had not dreamed he would pay as much as this.

For a moment Sin could not even feel sorry for Jamie. She just felt stunned.

If Seb had the necklace, he would have given it to Gerald in exchange for Jamie’s life. She was sure of that.

So who in the name of God had the pearl?

All Sin knew was that she did not.

She looked at Mae, and saw that Nick had grabbed her arm.

“You promised,” Nick murmured, low so only Mae and Sin could hear. “You promised me I could have first try. And I promised you I would take care of Jamie. Let me.”

Mae’s whole body was taut as a bow, taut with the longing to fly to her brother, but between her teeth she said, “Fine.”

Nick stepped forward. Sin looked at Jamie, his thin, bowed back and the expression he wore on his face, trying to look brave, and she was sorry for him then.

“Tell me, Mae,” Gerald said. “Where have you hidden the pearl?”

Mae looked at Nick. It was a nasty moment for Sin to remember that Nick couldn’t lie.

“You won’t kill him.” Nick’s voice rumbled in the center of his chest, lower than his usual tone. She thought it might be his version of uncertainty.

Gerald stopped toying with his ring.

“Watch me,” he said softly.

It was obvious that some of the other magicians were uneasy. Helen, who had put the sword through Jamie’s mother, looked like she wanted to be sick.

Sin had to wonder why they cared. She’d seen them set fire to her home, which could have had children in it, and then she remembered the way Helen had been with Lydie.

They thought magicians were the only real people in the world. They didn’t want to witness their leader killing one of their own.

Gerald was making a bad mistake. He would regret this.

Regret wouldn’t save Jamie. Sin didn’t dare move. Nick was unmoving as stone.

The one who moved was Jamie. Crouched there with the white stone of the Monument towering behind him, the Latin inscribed on it making it look like the tallest gravestone in the world, he looked small and helpless, his mouth trembling.

Sin saw that only one of his arms was chained. The other was free.

Between his skin and his sleeve, she saw a glint of metal.

The magicians thought that Sin had disappeared with the magic knife, the only weapon that could have cut her chains. They didn’t know that Sin had given it back.

What this called for was a diversion.

Sin stepped forward, tossing her hair over her shoulder.

“What if I have the pearl, Gerald?” she asked in a ringing voice. “I don’t care what happens to Jamie.”

“If you have the pearl,” Gerald said, and advanced on her, “I doubt you’re bright enough to have hidden it. We can just take it.”

A lick of fire burst from Gerald’s fingertips, turning into a rope of light headed straight for Sin.

It veered off into the sky abruptly when Gerald, the most recent in a long line of men who had underestimated Sin, had to dodge back from an arrow.

“Do you ever get tired of being wrong?” Sin asked as the magicians scattered, looking to the roofs.

None of them were looking at Jamie, as oblivious to him as the passersby along the dark road, making for the Tube and unable to see their little enchanted space.

Jamie brought the knife down with a crash on his chains.

The knife hit his chains and stopped as if it was made of plastic.

The magicians had not been fools enough to chain up a powerful magician with anything but chains that were enchanted themselves to resist magic. Sin froze in horror.

Everyone was looking at Jamie again now. The magicians murmured, a half-pitying and half-satisfied sound rippling from head to head. Gerald glanced back over his shoulder and laughed, light and mocking, as if at a stupid child.

Across gray stones and a dark sky, gold glinting far above him, Jamie’s magic-pale eyes narrowed to glowing lines.

He brought the knife back around, its blaze blurring the air around it, its hungry whine louder than ever.

Jamie launched himself to his feet, stumbling forward, free. The chains fell clinking to the base of the Monument.

Jamie’s left hand lay, severed neatly, palm up on the gray stones.

A trail of blood blazed scarlet behind him as he staggered forward, and several magicians stepped up to help him and then stopped themselves.

All but one.

Seb lunged forward and grabbed Jamie, both of them hurtling past Sin and landing practically at Nick’s feet. Sin glanced around and saw Nick on his knees, snarling something and touching Jamie’s arm. The blood stopped spurting from the horrible space where his hand had been, and they were all three crouched on the cobblestones, shirts covered with a vivid mess of blood. Jamie was sobbing, low and hoarse.

Sin and Mae exchanged looks. Mae had gone bone white, but as Sin met her eyes she nodded once, slowly.

Both of them drew their knives and stood protectively in front of the boys.

The sight of weapons galvanized Helen. She drew her sword and went for Sin, who parried the sword with one knife, then cut in at Helen’s ribs with the other. Helen only just managed to leap back and deflect the strike.

A blaze of magic flew at Sin from another magician’s fingers, and she had to throw herself back out of its path. She smelled the ends of her own hair burning.

All around them, arrows were let fly. Mae had hurled herself on the ground to escape them.

Helen attacked again, delivering a strike so hard that Sin held her knives crossed one in front of the other so both knives absorbed the impact of the blow, jarring the bones of her arms to the elbows. Sin saw another magician’s hands brighten and she ducked and dived, sliding on her belly on the cobblestones and snatching Helen’s ankle, pulling her foot out from under her.

She couldn’t keep dodging, she thought as she rolled and sprang back up. She could hold them off for maybe two minutes longer.

Nick rose from his crouch, and there was no more light glancing on the Monument.

The storm rolled in low. It felt as if the city of London had been swallowed at a gulp by some vast, hungry beast.

“You took my brother,” the demon said, and his voice echoed against that dense, dark sky. “Now you’ve crippled my friend. There is almost nothing else in the world you can do to me, and absolutely nothing else you can bargain with. All I want is to tear you to shreds!”

Lightning hit the Monument and traveled down and down, enveloping the whole stone column in a shimmering blanket of light. The light chased down the column to the ground in seconds, and when it hit, it hit two magicians.

It didn’t hit Gerald.

He said, “I command you not to hurt any member of my Circle. And I don’t think Jamie is in any state to counteract my order.”

A shudder passed through Nick, as if he was trying to ripple out of his own shape and become something else, anything else so long as it could leap at Gerald and destroy him.

Gerald’s lips curled.

Then his face was obscured.

The piping started, eerie and low, as if it came creeping with the mist over the broken cobblestones from the lightning strike. Every loose shard of stone began to rise, dancing in the air and then being hurled at the magicians.

The pipers of the Goblin Market were hidden on the rooftops, in the mist. The magicians had nothing to fight. Sin almost laughed in triumph, and then had to whirl out of the way of Helen’s sword, jumping in midair and twisting. She didn’t have to be better than Helen. She only had to be faster.

Then she looked around to check on Jamie. He was unconscious in Seb’s lap, Mae on her knees beside them. The wound where his hand had been was nothing but smooth skin, and his face, gilded by lightning, was gray and still.

Sin spun into engagement with Helen, making her knives a blur, almost dancing, going for the quick cuts to Helen’s arms and legs, holding her off and distracting her so she would let Sin move. She hurtled right into the path of Nick’s sword.

Nick checked his swing just in time and threw himself at her. Sin tumbled down to the cobblestones with Nick on top of her as Gerald’s latest fireball whizzed over their heads.

Nick took his weight on his arms, braced on either side of her. She was extremely grateful: It left her with enough breath to hiss, “Jamie’s in shock or worse. We have to get him some help! How much magic do you have left after healing him and causing a storm?”