Air rushed in Alex’s ears as he slipped down a curving, soft-walled tunnel. At first, he thought it was just the wind and the speed of descent. Then he caught its rhythm – air sucking downwards, then blowing back up the tunnel – and realized it was breathing.

He was falling inside the Water Dragon.

Alex flailed in panic. The walls of the tunnel were strangely sticky. He was sliding through gunk, which was thickening under his legs, slowing his descent enough to straighten up and regain control. A faint green light below his feet silhouetted his friends falling ahead of him.

“Brace yourselves!” Alex shouted.

Anil whimpered. “Why?”

“Because at the bottom of steep tunnels there’s usually a—”

Zoey and Anil dropped out of sight. The blowhole ended abruptly and Alex’s stomach lurched as he fell into empty air. Grey water rushed up from below. Alex threw out his hands to summon air bubbles around his friends’ faces before they splashed down.

Except there was no splash. The water didn’t swallow him up. It cratered softly underneath him, thick and cloying like treacle. Alex began to sink into the liquid as if being absorbed. It glooped around his legs, sticky strings stretching from his arms when he tried to wrench them clear.

Zoey floundered beside him, fruitlessly poking at the air bubble covering her nose and mouth. Alex slapped the surface of the gunk and both their bubbles popped.

“Go flat on your back and kick,” she said, pointing behind him.

An outcrop of jagged rock rose from the swamp. Alex stopped struggling and flattened himself evenly so he was no longer sinking. Then, carefully, he kicked both legs at once like a flipper to drive himself backwards.

Once he reached the outcrop, he dragged himself ashore. The grey-and-green rock was surprisingly brittle, crumbling to gravel under his hands. Alex heaved Zoey up beside him, their hands clamming stickily together.

“That might be the single most disgusting thing that’s ever happened to me.” Zoey scooped clear goop off her cheeks and out of her fringe. Rock dust had stuck to her hand and she rubbed it between her fingers. “Dragon bogies. We’re actually inside the dragon!”

She laughed – only a little manically – and Alex couldn’t help but join in. They had made it! Their most ridiculous plan yet had actually worked. The most dangerous part might still lie ahead, but allowing himself this moment of triumph made it seem distinctly less impossible.

Plus it distracted him from the horror of being covered head-to-toe in dragon snot.

“Where’s Anil?” he asked, sitting up so that slime sloughed off his skin.

Swinging movement overhead caught their attention. Anil hung upside down from a sticky green ribbon that had snagged his ankle. An air bubble sealed off his nose and mouth so they hadn’t heard his calls for help.

“I’m stuck on mucus,” Anil said as soon as the bubble was popped.

Their friend dangled too high above the snot rocks for them to reach. Alex moved to touch the mucus swamp, wondering if it would respond to his powers.

Zoey spoke before he could try. “Do you feel that? There’s something…”

She lifted her head and glanced around, as if expecting to find something watching them. Alex stood up and brushed himself off. There seemed to be magic everywhere. Heavy on the air, glowing from every wall. It almost teased the magic out from inside him as if he had sprung a leak.

Zoey was right. A presence lurked behind it. The same intruding darkness he had felt sapping his connections to the infected animals.

“You can feel it too?” Alex asked.

Zoey nodded, flexing her fingers experimentally as if she had lost feeling there. Maybe being so close to the source of darkness meant you didn’t need sea magic to sense it.

“I can feel it,” Anil called. “Also, I can feel all my blood pooling inside my head.”

“There’s an easy way to get him down.” Zoey picked up a craggy rock and let it fly. It hit Anil square in the chest and shattered into dust.

“Ow!” he cried.

“Just getting my eye in.” Zoey chose another stone and threw. This time it sliced through the mucus string, sending Anil head first into the swamp with a dull splat.

Zoey dusted off her hands. “Not going to pretend I didn’t enjoy that.”

After hauling Anil from the gunk, they took a moment to get their bearings. Salty air rushed over their heads, the blowhole high above their heads flexing and tightening.

“This must connect all the way up to the dragon’s lungs and nostrils,” Anil said. “Its body must be so huge that after air gets all the way down here it needs another way out.”

The airway walls quivered, wet and fleshy. Everywhere glowed dimly green, strings of mucus shining overhead like foul fairy lights. Slime was drying to a stiff crust on their skin.

“It smells like…” Zoey grimaced. “I actually can’t think of anything as disgusting as the reality.”

“We’ve smelled a lot of terrible things on our adventures, but this might be the worst,” Anil agreed.

He reached eagerly into his pocket and removed a sodden clump of paper that had once been his notebook. Anil allowed himself a crestfallen moment, before perking up again to take a camera wrapped up in a waterproof case from his other pocket.

“There’s absolutely nothing like this in the archive,” he said, snapping pictures in all directions.

“Photos of mucus.” Zoey shrugged her backpack off her shoulders. “Alert the media.” She opened the bag to check their supplies were still in one piece. Kraken snoozed safely in her bag, the natural sedative keeping her oblivious to their journey.

The rest of the bag clinked and clanked with empty vials and beakers. A larger bottle contained the pre-mixed cure recipe, awaiting a dose of zircongris to be complete.

“Meri asked me to take as many samples as I can,” Zoey said, scraping some mucus into a vial. “Argosy probably wants some too.”

Alex pressed a hand to his chest. The bottle of poison weighed heavily inside his pocket. He wouldn’t actually use it – he had only taken it to keep Argosy onside. That’s what he had told himself. But if they really couldn’t cure the dragon…

Deeper in the backpack, he spotted a tangle of wires. They threaded through the sides of the bag into its front pouches. Alex reached for them but Zoey stopped him.

“I couldn’t come here without a secret weapon up my sleeve,” she said tantalizingly.

“You should probably just tell us what it is so we can use it to not die,” Anil suggested.

Zoey wagged a finger. “That would be no fun.”

The last piece of equipment in the backpack was a walkie-talkie. Alex flicked it on and brought it to his mouth.

“We’ve—”

“Don’t forget your code name,” Zoey demanded.

Alex sighed. “Invasive Invertebrate has landed.”

A long moment of silence followed. They had accepted the risk that the thick walls of the dragon’s body would block the signal. Alex had simply hoped for a little luck.

Just as he was about to give up, the walkie-talkie fuzzed.

“Are Trembling Tapeworm and Doctor Dragon with you?” came Meri’s voice.

Zoey grinned. “And that’s why I like her.”

“We’re all here.” Alex spoke into the walkie-talkie. “Did everybody get away safely?”

“We joined the Dorothea before sailing clear. The baby dragon protected us from the worst of the weather. It’s getting so strong!” said Meri. “The storm wall opened to let us out. The dragon wanted us gone.”

“Stay at a safe distance and watch the storm,” Alex said. “If it begins to die away, that probably means the dragon is losing control to the parasites. Let us know right away.”

“We’ll come and collect you once you’ve delivered the cure. If not…” Meri trailed off. Nobody wanted to think about what would happen if they failed. “We can regroup and plan our next move.”

They had to act quickly to create and deliver the cure. If they didn’t make it in time, any next move they could make was unlikely to be enough.

“Speak soon. Stay safe.” Alex shut off the walkie-talkie. “Which way do we go?”

There was a pause before Anil realized they were looking to him for direction.

“Oh, you’re going to follow me?”

“You’ve worked the hardest on learning about all this stuff,” Alex said. “There’s no one better to lead us.”

Anil stood a little taller. “I’m just used to Zoey charging off so we have no choice but to follow.”

“Maybe it’s time we trusted somebody else then,” Zoey said with a smile.

Anil peered up at the blowhole and spun around like a compass needle to get his bearings. “We want to go down the dragon’s body. So it should be that way.” He pointed his camera across the mucus swamp, where it lapped against the far wall.

“I really don’t want to swim through that,” Zoey said.

“Maybe we don’t have to.”

Anil climbed a spear of snot rock and reached for a thick string of mucus dangling from the roof. It held his weight, and he kicked his legs to swing back and forth. More mucus hung like vines, all the way across the clammy quagmire. Momentum carried Anil close enough to grab the next string.

“Come on!” he shouted, swinging towards the next hold.

“Is it bad that a small part of me was hoping he’d fall into the mucus again?” Zoey asked.

“Yes,” replied Alex. “It would have been funny though.”

Zoey went first, climbing the rock and swinging out onto the mucus. Next, Alex grabbed the first vine. It squelched in his hand like wet rubber, grey water wringing from the tough slime. He swallowed down a shiver of revulsion and threw his weight forwards.

The mucus stretched but held firm. Alex quickly kicked his legs, already feeling the strain in his shoulder. He managed to swing enough that he could reach for the next vine with his free hand. The swamp blurred beneath him, momentum carrying him easily to the next string and the next.

“This is easier than I thou—”

A mucus string hit him in the face. He had caught up to Zoey too quickly and a vine she had just released had swung back into his path. Alex lost his grip and was knocked upside down. He prepared to give himself an air bubble as the swamp rushed up from below.

Something caught his ankle – Anil had loosed a lasso of mucus to wrap tightly around his foot. Dangling upside down, momentum swung him onwards. Zoey and Anil grabbed his hands and dragged him onto a dry bed of snot rock.

“Graceful,” said Zoey, helping him to his feet.

Alex brushed himself off. “I try my best. Where now?”

Anil pointed to a dark opening in the wall, lit dimly green by the dragon’s glow, hidden by a curtain of mucus and rimed with powdery snot. “It doesn’t exactly look inviting.”

“Let’s get moving. We have a long way to go.” Alex paused at the threshold of the opening. “Time to go into the belly of the beast.”

“We’re actually going into its bowel,” Anil pointed out.

“I know. I was doing a dramatic last line before we plunge into danger.”

“Oh, sorry!” Anil waved for him to carry on. “Do it again.”

Alex took a deep breath. “Looks like it’s time to…let’s just go.”

They parted the mucus curtain to begin their journey into the belly/bowel of the beast.