The pool chamber was quiet in the hours after the fight, apart from the gentle lapping of water against pale stone. The pool lit the ancient hall from below in soft, rippling waves of turquoise and silver, throwing long shadows across carved runes that had not seen light in three centuries.

Garnel Stoneblender sat cross-legged at the water’s edge with his grandmother’s leather journal open on his knees, surrounded by ticking copper callipers and brass lenses. Charcoal dust smudged his nose and his red hair stuck out in every direction, but behind his spectacles his eyes were bright with wonder.

“The magic isn’t gone,” he whispered, as Derek came over. “It was only sleeping. The pool draws from deep veins beneath the plateau, but the old channels run east. There are more chambers beyond that fallen wall. Sockets, altars, whole galleries.”

Derek looked at the far end of the room, where tons of shattered stone blocked the eastern archway. “That wall didn’t fall down by accident.”

“No,” Garnel agreed cheerfully. “Someone wanted to make very sure that whatever lay beyond stayed there. Or perhaps they were trying to keep something out.”

“That’s not cheerful,” said Derek.

“It’s interesting,” said Garnel, who did not always see the difference.

Behind them, propped against a pillar, sat Poopy Joe. Nibbles and Derek had carried him down from the landing, partly because Nibbles had insisted and partly because Derek did not like the idea of anything dead wandering about above them in the night. He sat upright in his ancient, peat-stained leather, smelling strongly of compost and ditch-water, and gazed sadly at the pool.

“He’s settling in,” said Nibbles, nudging one of Joe’s boots with his toe. “Look at him. He likes it here.”

Dave looked up from his spellbook. “Can zombies like things?”

“Joe can,” said Nibbles firmly. “And I’ve had an idea. The pool heals things. Joe is a thing. Joe needs healing. Lots of it.”

Nobody could find anything wrong with this, exactly, so they tried it. Thorn and Derek carried Poopy Joe down the steps, and Nibbles said “Vaelum Thrae” very firmly over the water, and they lowered him in.

Poopy Joe sank.

He sank straight to the bottom of the basin and lay there, gazing sadly up through the glowing water, while a long stream of bubbles rose from somewhere it was better not to think about. The water around him turned faintly brown.

They hauled him out. He was exactly as stiff as before, exactly as smelly as before, and now also wet.

“I think,” said Derek, wringing out his beard, “it’s more complicated than that.”

“It’s much more complicated than that,” said Garnel, who had watched the whole thing from behind his journal with an expression of mild horror.

Garnel peered at Poopy Joe over his spectacles with professional interest. “The pool’s waters carry healing,” he said slowly. “But Ethium magic is complicated. If I can understand how the old wizard bound him, perhaps the pool could wash out the rot and give him back his movement. It would take time. And a lot of Grandmother’s notes.”

“Take your time,” said Nibbles, settling Joe more comfortably against the pillar. “Just don’t let him wander off.”

“He’s a corpse, Nibbles,” said Derek. “He’s not going to wander off.”

Poopy Joe’s head tipped very slowly to one side.

Everyone looked at him. Nobody said anything for quite a long time.

---

They set watches by turns that night, the pool’s light painting the ceiling in slow, liquid waves.

It was on Dave’s watch, at around three in the morning, that Loki’s ears went flat. The dog gave a short, sharp huff and stood up, his nose pointed at the spiral stair.

“Thorn,” whispered Dave, touching the fighter’s shoulder. “Thorn. There’s people. On the stairs. Thorn. Are you awake? Thorn.”

“I’m awake,” said Thorn, who had been since the first Thorn.

Dark figures were slipping silently down the winding stair: not only survivors from the camp above, but fresh Hammer thugs and archers, sent from other camps across the plateau to take their tower back under cover of night. The Hammers, it turned out, had a much wider hold on Ethium than anyone had guessed. And at their head moved a tall, thin figure in a dark, trailing cloak that seemed to swallow the lantern light.

“Hammers!” shouted Thorn, bringing his shield up just as an iron-tipped arrow rang off his shoulder plate.

The chamber exploded into noise. Derek was on his feet in an instant, weapon drawn, while Loki charged the leading archer. Dave raised both hands and flung a bolt of crackling orange fire across the water that caught two thugs in the doorway. Garnel dived behind the nearest pillar and started firing bolts of his own, with a small apology after each one.

Through the chaos, Thorn saw the cloaked figure stop at the edge of the stairwell. Cold, calculating eyes gleamed beneath the deep hood. The stranger spared one long look at the glowing pool, at the four stones burning in their pillars. Then he turned on his heel and melted back up the stair.

While the Hammers fight, their cloaked leader watches the pool — then slips back into the dark.

“Stop him!” yelled Derek, striking down a thug who had lunged at Garnel.

Thorn bounded across the room, but the remaining Hammers threw themselves into the narrow stairway to cover their leader’s escape. By the time Thorn and Derek had cut their way through and reached the landing, the cloaked watcher was gone into the dark of the plateau, leaving only the cold night wind howling through the tower above.

“That’s twice,” said Derek quietly, staring out into the night. “The burial mounds. And now here.”

Thorn nodded. Neither of them said what they were both thinking: that whoever was under that hood had been following them all the way from Fallcrest.

Back in the chamber, Nibbles was already going through the fallen Hammers’ pockets. “Three copper,” he reported, “a comb, and a very old sandwich.” He held the sandwich up to the light, considered it, and put it in his pack.

“Nibbles.”

“You don’t know. It might be a good sandwich.”

---

The next morning, the companions gathered at the eastern cave-in, armed with iron pitons, picks and crowbars from the Hammer camp.

“The wizard’s notes are very clear,” said Garnel, handing over a rough sketch of the wall. “The main channels run straight through here. We must see what lies beyond.”

It took two whole days of hard, back-breaking work. Thorn and Derek levered huge blocks aside, grunting and straining, while Dave and Nibbles cleared the gravel and hauled away basket after basket of rubble. It was not, Nibbles pointed out frequently, the kind of work he had trained for.

“What did you train for?” asked Dave.

“Finding things. Opening things. Selling things.”

“Can’t you find the other side of the wall?”

Nibbles considered this, found that he had no answer, and went back to carrying baskets.

Dave was less help than he might have been, because Dave spent a great deal of the two days helping Garnel. Or rather, helping Garnel. He asked Garnel what every rune meant, and then what the rune next to it meant, and then whether runes had feelings. He picked up Garnel’s brass lenses to look through them, and put them back in the wrong place. He asked Garnel why he was so small, and whether all gnomes were that small, and whether Garnel’s hair was on fire or just red. He practised Garnel’s voice saying oh dear, oh dear, and thought it was the best impression anyone had ever done. And once, while Garnel was carefully measuring the angle of a groove in the floor, Dave leaned right over him to see, so that his shadow blotted out the copper dial, and Garnel made a small strangled noise that sounded a great deal like the orc had looked.

By the end of the second day Garnel had started taking his notes to the far side of the pool, and then behind a pillar, and then behind a slightly bigger pillar.

“I think,” said Derek quietly to Dave, “that you might be annoying Garnel.”

Dave was astonished. “I’m helping him.”

“I know you think so,” said Derek.

On the second afternoon, a narrow gap opened at last near the top of the rubble, barely big enough for a small bird.

Dave nudged Peggy off his shoulder. The pseudodragon spread her leathery wings, squeezed through the dusty gap and glided off into the dark beyond. For a moment there was only silence. Then a soft, satisfied chirp echoed back through the stone.

“Pegs says it’s clear,” said Dave, eyes closed, seeing through hers. “Smooth walls. Tall arches. Safe to cross.” He opened one eye. “She says it’s also very dusty, and she’s not happy about it.”

They widened the gap. Nibbles squirmed through first, then Dave, which took some time because Dave was six foot seven and the gap was not, then Derek, then Thorn, and last of all a wide-eyed Garnel, clutching his folders tight against his chest.

“It opens up!” called Nibbles. “Smooth walls! Ethium work!”

---

Beyond the collapse lay a grand Ethium corridor, its pale marble blocks smooth and perfectly joined. Fifty yards along, it opened into a high vaulted gallery lined with statues.

At the near end stood carved figures of Ethium citizens in long flowing robes. At the far end stood stern dwarf lords carved from dark granite. And along both walls between them stood eight towering warriors carved from pale, veined stone, each holding a huge halberd. Above their heads, many of the carved sockets stood empty, their stones lost or looted long ago. But above three of the warriors, pale blue Ethium Stones pulsed with a slow, sleeping light.

“It’s a border,” whispered Garnel. “Ethium on one side, the dwarves on the other. And guards in between.”

“Guards,” repeated Thorn slowly.

The companions stepped out into the gallery together.

The moment they did, the three stones flared. The intruders had been noticed. The three warrior statues with stones above them turned their heads in perfect unison, their eyes blazing with pale light, and stepped down from their pedestals with a thud that shook dust from the ceiling.

“Guards!” shouted Derek, drawing his weapon, as Garnel squeaked and ducked behind him. “Border sentries!”

“I said they were guards,” said Dave, who had not.

Thorn met the leading statue head-on. His axe struck its stone arm with a ringing clang, and left nothing but a faint scratch. The guardian swung its huge halberd in a wide arc and slammed him back against the wall.

“Iron won’t bite them!” Thorn gasped, barely catching the next crushing blow on his shield.

Nibbles ducked under a sweeping blade and stabbed uselessly at a statue’s leg. “It’s like fighting a mountain!” He looked at the leg more closely. “A very well-made mountain. This is quality stonework. Do you know what one of these would fetch, in a nice garden?”

“Nibbles!”

Dave crouched behind a pillar, scanning the gallery with eyes that had stopped being a seven-year-old’s for a moment and become something much sharper. “The stones!” he shouted. “The stones in the sockets! They’re powering them! Get the stones out! But don’t break them, we need them!”

Three ancient border guardians step down from their pedestals — and the party discovers what powers them.

“Thorn, hold the line!” called Derek.

Thorn held it. He and Loki drew the guardians’ fury, giving ground, blocking and dodging, while the others went for the stones. Nibbles scrambled up the nearest pedestal, dodged a stone elbow, and jammed the tip of his dagger under the first stone, popping it loose. He threw himself sideways as it fell and caught it cleanly in both hands before it could shatter on the floor. The statue looming over Thorn went instantly stiff, the light dying in its eyes, and froze into an ordinary monument.

“Mine,” breathed Nibbles, holding the stone up to the light.

“Ours,” said Derek, levering the second stone out with the handle of his weapon and catching it in his mailed glove.

Dave cast a spell of pure pushing force that popped the third stone free and guided it gently through the air into his waiting palms. “I meant to do that,” he said, before anyone could ask.

One by one, the three stone guardians fell silent, and the gallery was still again.

“Not bad,” said Nibbles, admiring his stone with an enormous grin. “Tricky catch, but definitely shiny. And worth at least—”

“Nibbles.”

“I was going to say a lot.”

---

Beyond the Hall of Statues, the corridor ended suddenly at a terrible drop.

An ancient Ethium bridge had once crossed the vast underground chasm here, but it had fallen long ago, and its broken spans hung over empty air. The cavern opened into a dizzying underground vault: a sheer fifty-foot drop from their ledge straight down to a pitch-black lake far below. Seventy feet away across the gap, and fifty feet above the dark floor, a narrow archway on the opposite cliff showed where the corridor carried on.

Thorn anchored two heavy ropes to a sturdy stone pillar. Garnel took one look over the edge, went pale, and backed away, clutching his notes.

“I… I shall stay up here at the ledge,” he stammered. “I can guard the ropes. And watch your descent. And not be down there.”

Thorn nodded, and the four companions climbed down the cliff face into the damp, echoing shadows below.

The cavern floor was a nightmare of shattered rubble, slick rock and a slow, pitch-black lake fed by a trickle from the roof. At the foot of the western cliff gaped a foul cave mouth heaped with rotting carcasses and rubbish.

“Phew!” Nibbles gagged, holding his sleeve over his snout. “What in the seven hells is that?”

“Rubbish,” said Derek grimly, inspecting the pile of bones beneath the cave mouth. “Whatever lives up in those tunnels throws its scraps down here.”

“Why?” asked Dave.

“I don’t want to find out,” said Derek.

Dave took a step towards the edge of the black lake, his torch throwing long orange flickers across the water. And suddenly a voice spoke inside his head: soft, sorrowful, clear and desperate.

Please… help me… I’m trapped beneath the stones… so cold…

Dave blinked. He took another step towards the water. “There’s someone down there,” he said. “Someone’s trapped in the water. They need help.”

“Dave, wait,” said Derek sharply, reaching for his shoulder. “Don’t go near the edge!”

Before Dave could step back, the black water exploded upwards. A huge rubbery body, five feet across, burst out of the sludge on three thick stumpy legs. Two enormous muscular tentacles tipped with spiked suckers lashed out, caught Nibbles around the waist, and hauled him off his feet with a yelp.

It was, everyone agreed later, very typical. Something always grabbed Nibbles.

“Otyugh!” roared Derek.

The black lake erupts — and Nibbles is dragged towards the Otyugh’s maw.

“Form up!” barked Thorn, charging across the slippery rocks with his shield raised. “Derek, left! Dave, fire!”

The creature’s mouth gaped open in the middle of its body: a nightmare ringed with three rows of yellow teeth. It dragged Nibbles towards it and bit deep into the shoulder of his armour.

“Get off me, you oversized turnip!” screamed Nibbles, flailing with his dagger. “Do you know how much this armour cost?”

Thorn closed in fast, his shield up to catch the second lashing tentacle. Swaying under a crushing sweep, he swung his battleaxe one-handed across the tentacle that held Nibbles. The blade bit deep into the rubbery hide. The beast let out a wet, gurgling shriek and let go, dropping Nibbles into the black mud.

“Fall back, Nibbles!” Thorn commanded, stepping squarely between the monster and the rogue before the other tentacle could snatch him again. “Dave, now!”

Dave hurled a bolt of fire. And from fifty feet above, a second streak of bright orange flame shot down from the clifftop. Garnel was leaning out over the ledge, peering through his spectacles and firing bolts down into the lake.

“Take that, you foul beast!” Garnel squeaked from far above. “Sorry! No! Not sorry!”

The double blast of spellfire burst across the creature’s rubbery back and filled the cavern with the smell of scorched sludge. Derek rushed into the shallows, his weapon glowing with holy light, and struck it hard in the side. The otyugh thrashed wildly, sending black water splashing thirty feet into the air, and then collapsed back into the lake with a heavy, gurgling splash.

Silence returned to the cavern, apart from the sound of Nibbles coughing up mud.

“Is everyone alive?” said Thorn, pulling Nibbles out of the shallows.

“Barely,” wheezed Nibbles, rubbing his ribs. “I tasted it. It tastes of rotten cabbage and regret.” He looked up at the ledge. “Nice shooting, Garnel!”

“Yes!” shouted Dave, delighted, cupping his claws round his snout. “Good shot, Garnel! For a really small person!”

There was a pause from the clifftop.

---

Garnel did not come down.

When he spoke again, his voice drifted down from the ledge, small and tired and very polite.

“That was far too close,” he called, adjusting his spectacles with shaky fingers. “Steep drops, living statues, giant lake monsters. And…” He hesitated, and somehow everyone below knew he was looking at Dave. “And it has been a very long two days. I think that everything further on is a little too much for me. If it’s all the same to you, I shall go back to the pool. I can study the wizard’s notes, and keep an eye on the stones, and see what the water can do for Poopy Joe. In peace.”

Thorn looked at Derek. Derek looked at Dave. Dave looked at his boots.

“I was only being friendly,” said Dave in a small voice.

“I know,” said Derek, not unkindly. “But Garnel likes quiet. And you’re not very quiet.”

Dave thought about this for a long moment, harder than he had thought about anything all week.

“Sorry, Garnel!” he shouted up at the ledge. “Sorry about your hair! And your lenses! And the oh dear, oh dear!”

“It’s… quite all right,” came Garnel’s voice, sounding as though it was very nearly all right.

“He’ll do far more good back at the pool,” said Thorn, and he meant it. “That’s where his work is. And somebody needs to watch over Joe.”

They all agreed. The pool was safe now, and they would know where to find him. Garnel waved from the ledge, a small figure against the dark, and turned back towards the Hall of Statues with his folders clutched to his chest and his red hair glowing in the torchlight. They watched him go until the dark swallowed him up.

“He’s nice,” said Dave.

“He is,” said Derek. “You’ll make it up to him.”

“How?”

“You’ll think of something.”

---

Searching the muck near the stinking cave mouth, Derek spotted a rusted iron chest wedged between two rocks: all that was left of some long-forgotten party of adventurers. Inside, wrapped in oiled leather, they found a pouch of silver coins and a small glass vial of glowing red liquid.

“A healing potion,” said Derek, handing it to Thorn. “We’ve earned it.”

Nibbles counted the silver twice and looked almost happy, which for someone who had just been half eaten by a monster was quite an achievement.

Then they turned towards the eastern cliff, where the high archway waited, fifty feet up the sheer wet rock, and beyond it the dark, unknown halls of the duergar.