"Macaulay!" a harsh, thin voice called out.

They all stopped in their tracks and wheeled around. The fog was patchier here on the higher ground, and through the thinning wisps they saw a lone figure. It was a single Styx. He stood there, tall and arrogant, with his arms folded across his narrow chest.

"Well, well, well. Funny how rats always use the same runs…" he shouted.

"Crawfly," Tam replied coolly as he pushed Cal and Will toward Imago.

"…leaving their grease and stinking spoor on the sides. I knew I'd get you one day; it was just a matter of time." The Crawfly uncrossed his arms and then snapped them like whips. Will's heart missed a beat as he saw two shining blades appear in the Styx 's hands. Curved and about ten inches long, they looked like small scythes.

"You've been a thorn in my side for too long!" the Crawfly yelled.

Will glanced at Tam and was surprised to see he was already armed with a brutal-looking machete he seemed to have conjured from nowhere.

"It's time I righted a few wrongs," Tam said in a low, urgent voice to Imago and the boys. They could see the look of grim determination in his eyes. He turned in the direction of the Crawfly. "Get going, you lot, and I'll catch up to you," he called back to them as he began to advance.

But the saturnine figure with swathes of fog curling around it didn't give an inch. Brandishing the scythes with an expert flourish and crouching a little, the Styx had the appearance of something horribly unnatural.

"This isn't right. He's too bloody confident," Imago muttered. "We should make ourselves scarce." He drew the boys back protectively to one of the tunnel mouths of the Labyrinth as Tam closed in on the Crawfly.

"Oh, no… no…" Imago drew in his breath.

Will and Cal turned, searching for the source of his alarm. A mass of Styx had appeared through the mists and were spreading out in a wide arc. But the Crawfly held up one glinting scythe and they came to an abrupt halt a little distance behind him, swaying and fidgeting impatiently.

Tam stopped, pausing for a moment as if weighing the odds. He shook his head just once, then drew himself up defiantly. He tore off his hood and took a large breath, filling his lungs with the foul air.

In reply, the Crawfly yanked off his goggles and breathing apparatus, dropping them at his feet and kicking them aside. Tam and the Crawfly both stepped closer, then stopped. They faced each other like two opposing champions, and Will shuddered as he spotted the cold, sardonic smile on the thin face of the Styx.

The boys held their breath. It had grown so deathly quiet in that place, as if all the sound had been sucked from the world.

The Crawfly made the first move, his arms whipping over each other as he lunged forward. Tam jerked back to avoid the barrage of steel and, stepping to the side, brought up his machete in a defensive move. The two men's blades met and scraped off each other with a shrill metallic scream.

With incredible dexterity, the Crawfly spun around as if performing some ritual dance, darting toward Tam and back again, slashing and slashing with his twin blades. Tam retaliated with thrusts and parries, and the two opponents attacked and defended and attacked in turn. Each sally was so blisteringly fast, Cal and Will hardly dared blink. Even as they watched, there came another salvo of silver and gray, and the two men were suddenly so close they could have embraced, the razor-sharp edges of their weapons grinding coldly against each other. Almost as quickly, they fell back, breathing heavily. There was a lull while each man's eyes remained fixed on the other's, but Tam seemed to be listing slightly and clutching his side.

"This is bad," Imago said under his breath.

Will saw it, too. Between Tam's fingers and down his jacket seeped dark ribbons of liquid, which looked more like harmless black ink under the green light of the city. He was wounded and bleeding badly. He drew himself slowly up and, apparently recovering, in a flash had swung his machete at the Crawfly, who sidestepped effortlessly and swiped him across the face.

Tam flinched and staggered back, Imago and the boys saw the patch of blackness now spreading down his left cheek.

"Oh my God," Imago said quietly, holding on to the boys' collars so tightly that Will could feel his arms tensing as the fight resumed.

Tam attacked yet again, the Crawfly whirling backward and forward, this way and that, in his fluid and stylized dance. Tam's swipes and thrusts were decisive and skillful, but the Crawfly was too fast, the machete blade time and time again meeting with nothing but misty air. As Tam was twisting around to face his elusive opponent, he lost his footing. Trying to straighten up, his boots were slipping hopelessly. He was off balance, in a vulnerable position. The Crawfly couldn't miss this opportunity. He lunged at Tam's exposed flank.

But Tam was ready. He'd been waiting for this moment. He ducked forward and rose inside his opponent's guard, bringing up the machete in a flash, so smartly that Will missed the devastating slash to the Crawfly's throat.

The air between the two combatants filled with dark spume as the Crawfly reeled back. The Styx let both of his scythes tumble to the ground and gave out a bloody, hissing gurgle as he clutched his severed windpipe.

Like a matador delivering the killing blow, Tam stepped forward, using both his hands for the final thrust. The blade sank up to the hilt in the Crawfly's chest. He let out a bubbling hiss and grabbed Tam's shoulders to steady himself. He looked down with sheer disbelief at the rough wooden handle protruding from his sternum, then raised his head. For a moment they stood there absolutely motionless, like two statues in a tragic tableau, staring at each other in silent recognition.

Then Tam braced one foot against the Crawfly and wrenched out his machete. The Styx teetered on the spot, like a puppet suspended by unseen wires, his mouth shaping empty, breathless curses.

They watched as the mortally wounded man spluttered a last choking snarl at Tam and, tottering backward, collapsed to the ground in a lifeless heap. Excited whispers passed down the lines of Styx, who seemed paralyzed, unsure of what they should do next.

Tam wasted no time in such hesitation. Holding his injured side and grimacing with the pain, he sprinted back to join Imago and the boys. This in turn mobilized the Styx, who scuttled forward to form a ring around the body of their fallen comrade.

Tam was already leading Imago and the boys down a Labyrinth passage. But they had hardly gone any distance when he lurched to one side and sought out the wall for support. He was breathing hard and sweat was pouring off him. It streamed down his face, mingling with the blood from his lacerations and dripping from his bristly chin.

"I'll hold them off," he panted, looking back at the tunnel opening. "It'll buy you some time."

"No, I'll do it," Imago said. "You're wounded."

"I'm finished anyway," Tam said quietly.

Imago looked down at the blood welling out of the gaping flap on Tam's chest, and their eyes met for a fraction of a second. As Imago handed him his machete, it was clear the decision had been made.

"Don't, Uncle Tam! Please come with us," Cal begged in a choked voice, knowing full well what this meant.

"Then we'd all lose, Cal," Tam said, smiling wanly and hugging him with one arm. He reached into his shirt and yanked something from around his neck and pressed it into Will's hand. It was a smooth pendant with a symbol carved into it.

"Take this," Tam said quickly. "It might come in useful where you're going." He let go of Cal and took a step away, but then grabbed hold of Will, his eyes never leaving the younger boy. "And watch out for Cal, won't you, Will?" Tam tightened his grip on him. "Promise me that."