The tunnel they were sheltering in led downwards. It wasn't one William or anyone had explored before – untapped veins of the original ores, like copper and iron, still embedded the walls, along with some new ones. They found a small amount of Cobalt and even a vein of Mythril on the way down into the stone layer.

The caves were thankfully mostly empty of enemies, only a few Giant Bats and a skeleton wearing dark blue armour raising their heads. The armoured skeleton ended up dropping a new sword after William had cleaved away all its life with his Cutlass.

"Geez, how many swords are you getting, William?" Sid said, smiling.

William inspected it. It was a Beam Sword – it dealt even more damage than the Cutlass and, as its name implied, shot a beam shaped like a sword when he swung it.

It was at that moment that a stringy projectile wrapped itself around Meg and pinned her to the wall.

William spun around just as a giant spider – a Black Recluse – landed on him. He cried out as it bit into him, dealing a massive 162 damage. He swung his Beam Sword, hitting it twice – once with the sword itself and once with the beam – but the spider was barely knocked back.

"Don't let them touch you! They hurt!" Sid shouted as his Imps flew forward and began cooking the spider with fireballs.

"I noticed!" William muttered as he threw up his Ruby Hook to grapple up to the ceiling, out of the spider's reach. He threw his Flamarang down, hitting the spider in the cephalothorax, then realised his Beam Sword would probably do more damage and started swinging wildly downwards, sending forth several magical sword-beams that impaled themselves into the spider.

After they'd slain the spider Sid and William freed Meg from the webbing.

"Ugh, that takes me back to being imprisoned in the Queen Bee's larva," she groaned.

"There must be a spider cave close by," Sid said. "I can farm out their Spider Fangs here. How about while I do that, you two head deeper down to search for Titanium?"

"Are you sure splitting up is the best idea?" Meg asked.

"I'll keep out of sight and get my minions to do the attacking," Sid said, then he pulled a bed out of his inventory and placed it on the cavern floor. "And if one of them spots me, I can just Magic-Mirror out of there."

"Splitting up probably isn't such a bad idea," William agreed. "We need to get geared up as fast as possible. The citizens are being held hostage."

"Okay," Meg said, "But if you get caught up in a spider's web, Sid, I'll just say 'I told you so'."

***

Deeper down, William and Meg came across a large vein of Mythril that contained enough ore for them to craft another anvil. Beyond that, William spotted a golden chest.

"Do you think the chest loot changes at all?" he wondered out loud.

"Maybe," Meg murmured. "But I'd be careful. The first gold chest I found in the jungle turned out to be rigged with traps all around it. The five dart traps pointing directly into it from either side were a dead giveaway, but then I found boulder traps above and some explosives buried beneath it. Even after disarming them I was too scared to open it."

"This one's probably safe," William said as he placed some torches around it. "I don't see any dart traps."

He took a step towards it, but that was when the chest leapt at him.

"Aigh!" he cried.

It was a Mimic. Several sharp teeth sprouted from its lid as it heaved open and bit him on his arm, dealing 144 damage. He swung his Beam Sword at it, which only stunned it for a split second before it leapt at him again. He weaved to the side, causing it to miss and come into contact with the fireballs Meg had cast. The two of them kept on attacking with ranged attacks, the Mimic constantly trying to leap at both of them but not making any progress towards either, before breaking apart into gold-plated wood. Over two dozen gold coins dropped amongst its remains along with a gold-tipped dagger.

Meg picked it up. "Hey, this is a Magic Dagger!"

"Oh, nice!" William said.

She tried throwing the dagger at a wall, then looked down to see the dagger was still in her hand.

"About time I got something new," she smiled.

The next cavern they went into contained a bat that glowed a bright magenta, which was easily spotted and defeated in the darkness. At that same moment a humanoid figure, similarly glowing purple, materialised out of thin air and leapt at William, making to pummel him with fists.

William slashed at the figure, noting that it was named a 'Chaos Elemental.' He landed three hits before it disappeared.

"Huh," he said. "It didn't look like all its life had gone yet –"

He was hit from behind. He spun around, bringing his Beam Sword into Chaos Elemental.

"This thing can teleport!" he shouted.

A few more slashes and it disappeared again, though this time William was sure it had been defeated since it dropped some silver coins and a glowing pink orb that, unlike other items, hovered in mid-air before William picked it up.

"A Soul of Light," he read. "The essence of light creatures."

"Sid and I found a few like those before," Meg said. "Except they were named Soul of Night, and they came from the Crimson. I guess we must be underneath the Hallow biome."

The Hallow on the surface had appeared like a child's fairytale, with pixies and unicorns and rainbows. It seemed like the enemies of the Underground Hallow leaned more into a pink-energy theme.

He took some steps forward and gasped as he emerged into a large cavern studded with pink and blue lights, which appeared to be glowing crystals. He could see more of the glowing pink bats and some slimes of the same colour.

"It's... beautiful," he gasped.

"That's the Hallow in a nutshell," Meg said. "Beautiful, but trying to kill us as much as the Crimson."

They investigated the area. William tried picking up a few of the glowing crystals from the wall with his pickaxe, finding they dropped an item named 'Crystal Shard.'

"This tunnel leads to an icy section," Meg called. "We must be under the snow biome as well."

The pearly-white stone gave way to ice imbued with streaks of pink. The first enemy they came across there was an Icy Merman that tried shooting glowing icy fragments at them, though Meg's fireballs quickly melted it. It dropped an icicle-like item that rushed into William's inventory.

"Frozen Key," he said, but was interrupted by the pink dragon that appeared in front of him.

It wasn't a huge dragon, only the size of a Mother Slime. Named 'Pigron' – pink dragon, or perhaps pig dragon based on the rather distinctive snout it had. He didn't have much more time to discern details as it flew at him, making a high growl that sure sounded like a pig. He cut it to bits with his Cutlass.

He turned to find Meg facing down another Chaos Elemental, but she had it under control, throwing Magic Daggers at it as fast as she could. Even when it tried to teleport around her she'd always spin around and keep up the attack. It soon vanished into the ether, leaving behind a magenta staff.

"It dropped a Rod of Discord," Meg announced.

"That sounds like another magic weapon," William said. "What does it do?"

"Um... it doesn't say. No magic damage listed or anything..."

"Huh." It suddenly occurred to William to check the Frozen Key that had popped into his inventory. It just said it was 'cursed by a powerful Jungle creature,' not giving any hints as to what it unlocked.

Going even deeper soon melted down the ice caves into lava-filled tunnels. The enemies were often prone to accidentally walking straight into lava and dying, sometimes leaving behind coins or other drops. One green-armoured Skeleton Archer left behind a Marrow, which was apparently a bow fashioned out of a leg bone. If Robyn had been there, she would have appreciated this weapon.

Robyn...

"That looks like it might be some Titanium over there," Meg said after some time. William stared hard at the seam of shiny, silvery ore as she pointed it out. It look was similar to that of silver ore, but with a darker tone that made it appear much stronger.

Meg cautiously approached the ore, stopping as an Illuminant Slime dropped down from above in her path, which she silenced with some Magic Daggers.

That was when William noticed something hidden in the shadows to the left. "Meg! Watch out-"

The thing leapt forward, just like the Mimic that had attacked them earlier. In fact, this thing was a mimic as well, but one much bigger, coloured aquamarine and magenta, and ornately decorated. A tongue stuck out as it leapt, and Meg screamed.

The Mimic slammed into her with the force of a freight train, sending her careening off a ledge.

And into a lake of lava.

"No!" William cried, running forwards and peering down into the pond.

There was no sign of Meg.

The Mimic's attack didn't stop for a moment. William snapped out of his shock just in time to use his Shield of Cthulhu to dash to the side, dodging the Mimic's next lunge. He swung his Beam Sword, landing a glancing blow with the sword's beam. He got a glimpse of the Mimic's label – it was a Hallowed Mimic, with 7000 life. Way more than the other Mimic – it was practically a boss in its own right.

The Hallowed Mimic's next move was to jump up and try to slam down on top of William, but he dodged once again.

That was when Meg dropped down on it, Magic Daggers flying. She was on fire and had lost a lot of life, but was alive.

"I figured out how that Rod of Discord worked!" she cried. "It let me teleport out of the lava!"

Relief flooded William's soul. "Great!"

He kept up his attack, but Meg's Magic Daggers dealt way more damage, and she teleported around enough times that the Hallowed Mimic could barely keep track of her. A few times it tried to close up to protect itself, at which time it deflected projectiles – the first time this happened William nearly got skewered by his own sword-beam, and Meg likewise with her Magic Daggers. But before too long they brought it down, and it dropped a bunch of healing and mana potions, some gold coins, and a knife with a crystal hilt.

"It's a Flying Knife," Meg said. "Melee weapon. Here, William." She tossed it at him. It arced through the air and landed in his hands.

"Thanks."

***

Titanium began getting a bit more common from there on, but when they reached the Underworld they realised the new ores often spawned embedded in the ash ceiling, and it was easy to spot them this way considering the Underworld's size. The enemies of the Underworld had surprisingly barely changed – in many ways they were actually easier to kill than the new ones that appeared post-Guardian's defeat. There were a couple of Shadow Chest mimics, one of which dropped an upgraded Grappling Hook that William equipped, but other than that it was smooth sailing.

Until they encountered a strange human wearing a black top hat and mauve cloak, labelled as a 'Tortured Soul'. It wasn't an enemy William had encountered before, and Meg was so surprised at its appearance that she accidentally threw some Purification Powder that she'd bought from the Dryad at it instead of her Magic Dagger.

Yet somehow that actually affected it. Its skin lightened, pupils returned to its eyes, and it gained a different label. 'Theodore – 250/250'.

The man looked around, his eyebrows furrowing on his wrinkled face. "Where the hell am I?"

"In... hell, basically," Meg said, looking surprised at his sudden transformation.

"Who are you?" William asked.

"I am Theodore, the Tax Collector," the man said. "Here to make sure the townsfolk are always payin' up. Livin' ain't free, I tell you!"

"Well... right now all the citizens are being held hostage by pirates," William said, "Not sure how –"

"Pirates? Those scum think they can live outside the law, sailing around on their ships and never giving their taxes to anyone? Cheaters, I tell you."

"Well... I guess," William said.

"Point me in the direction of them, and I'll give their skulls a good crackening!" Theodore raised his cane threateningly.

"Okay, okay, good to hear," William muttered, then turned to Meg. "Do you think we have enough Titanium?"

"It'll have to do. We should go back anyway and check on Sid."