William stared hard at her.

It... it can't be...

Robyn made the first move. She thrust out her Hellwing Bow and began firing rapidly.

William only had a split-second to react, bringing up his shield to block the bats. He glanced back just in time to see Meg and Sid flying towards him.

Sid was the first to attack, swinging out his new Firecracker whip at Robyn's side.

"Snap out of it!" he shouted. "Or my Imps will open fire!"

She didn't, instead drawing her other bow – The Bee's Knees – and began firing bee-arrows at him. Sid tried to dodge but her aim was true and the bees broke apart in formation to chase after him. Before too long he fell to the ground, screaming as the killer bees swarmed all over him.

Meg was next, casting bouncing fireballs at Robyn with her Flower of Fire, but William watched in horror as she drew the shiny blue blade of a Muramasa – a weapon he had no idea she'd had. She jumped up and slashed Meg out of the sky.

William cried out and sandstorm-jumped at Robyn, Night's Edge swinging. She blocked with her Muramasa, but William's momentum pushed against her and sent them both falling to the ground. Upon scrambling to their feet Robyn charged and made several rapid strikes. It was all William could do to parry each swipe with his larger sword, but he couldn't fight back – he couldn't hurt her.

The girl that he liked.

Robyn accelerated her attacks, and before too long a swipe caught William's wrist, causing him to drop his Night's Edge. He cried out as more sword swipes raked across his Molten Armour. His life dropped fast, and Robyn only stopped, holding her blade against his neck, when his life had reached 15. Another hit would kill him.

"It is time to execute you all."

Her voice... it was so dark and otherworldly. There was no way this was Robyn.

His thoughts were interrupted when a golf ball conked Robyn on the head.

He craned his neck to see Harry the Golfer. The Zoologist and Witch Doctor stood some distance behind him.

"Big mistake," Robyn said. "I would have spared you."

William watched, horrified, as she dashed at the Golfer, using a Shield of Cthulhu of her own, and cleaved her Muramasa straight through the Golfer's chest.

His sister screamed as he was split apart.

William's stomach sank.

His eyes fell to the pieces of the Golfer as they rolled across the ground. An arm, a piece of torso... his head...

The brutality...

He forced himself to look away, to look at Robyn, as she turned back to face him.

"You're next."

That was when Sid came flying forward and screaming a battle cry. He was propelled by his Frostspark Boots, his Minishark and Imp summons firing. Robyn took a lot of the hits, her life falling fast, but she just nonchalantly pulled out a Magic Mirror and disappeared.

William gasped.

He'd been so sure... so certain that their journey had been over.

The ancient spirits of light and dark have been released.

But it was only just beginning.

The world's guardian has been defeated. Now nothing stands in their way.

And Robyn...

She was gone.

***

"...and right as the Wall of Flesh fell," Sid finished, "I heard whispering in my ear. We all did, from some... voice. The ancient spirits of light and dark have been released."

William watched the Dryad closely. Her expression had been like stone ever since Sid had started recounting the story, and now she seemed to be deflating.

"And right after, that was when Robyn turned against us. She killed Harry and almost killed the rest of us, but we drove her away."

"What did she say to you again, William?" Meg asked.

William blinked, fazed at the sudden question. "Uh... that the world's guardian has been defeated, and nothing stands in... their way."

"What does all this mean?" Sid muttered.

"Well..." the Dryad pursed her lips. "To begin with, the world has a Guardian, who serves as the world's master and core."

"And Robyn said it had been defeated... wait. Are you meaning the Guardian was... that wall thing?"

"Appearances can be deceiving," Nissa said. "The Guardian may have rested in the Underworld, and had a form that could cause some to believe it had links to the Crimson, but in truth its role was to keep the world intact and in balance. The Crimson existed, yes, but the Guardian kept it in check, allowing it to thrive without overcoming everything."

It was then that William noticed that Nissa didn't seem too happy about the situation.

"Are you saying the Crimson could consume the whole world? Now that the Guardian is gone?" Meg asked.

"Actually, it probably won't," the Dryad said. "There is one contingency the Guardian had set in the event of its death. It unleashed the spirits of light and dark. While this will amplify the Crimson's coverage, it has also created something new – the Hallow."

The Hallow? Another biome?

"The Hallow functions as an overcompensation of purity, taken to the absolute extreme. It might appear friendly and happy on the surface, but underlying all the glitter, it similarly seeks to cover the whole world before the Crimson can. It is on no side but its own."

William looked between Meg and Sid. Meg looked worried at this, though Sid didn't seem fazed. If anything, he almost looked excited at having the opportunity to explore another new biome.

And William himself... he didn't know what to think. His mind was still back in another place.

A very... dark place.

"Let's get back to Robyn," Meg said. "Do any of you have any idea why she suddenly switched sides like that?"

"William knows her better than me," Sid said. "What do you think?"

William felt unease rising as the two of them stared at him. It was bad enough that Robyn had just betrayed them, but talking about it would only mean reliving the worst memories he now had of this world.

The way she had... murdered the Golfer in cold blood, eviscerating him with a sword like what William often used. The look in her eyes as she'd turned to him. Glowing red, darkness around the edges.

But looking back on it now, he realised it wasn't on Robyn that he had first seen those eyes. He'd seen them somewhere else before.

"The Old Man," he blurted.

Sid looked at him oddly, Meg looked at him confused.

"I think she was possessed. Cursed. Like what James the Clothier was before we fought his master, Skeletron. Before we freed him."

Sid gasped. "Are you sure?"

William could only nod.

"If that's the case, then it is clear that the Cultists from the Dungeon are still at large," Nissa said. "Hiding, but still active and a very real threat."

"It must've been a Cultist that shot the fireball that knocked Andrew into the lava," Meg added. "They have very powerful magic on their side."

"Ungodly magic," Nissa agreed.

"Speaking of Andrew, remember what he said?" Sid asked. "He told us the Order of the Guides specifically sent him to change the world, which happened when we defeated the world's Guardian."

William remembered. "He said that... we were fit for the purpose he guided us to."

"Which turned out to be destroying the Guardian, disrupting the balance of the world!" Meg exclaimed.

"He's been using us all along," Sid groaned.

"The Order of the Guide does not work like that," Nissa said. "They are dedicated to the preservation and distribution of knowledge."

"Then why did they send him to essentially make us destroy the Guardian?" Sid argued. "If anything, they've probably given the Cultists exactly what they want. A Cultist was ultimately the one to knock him into the lava, summoning the Wall. Right after we defeated it, Robyn tried to take out the rest of us!"

"Nothing about this sounds good, I agree," Nissa said. "But the Order must have had some other reason for destroying the world's Guardian."

Now nothing stands in their way, William found himself thinking, remembering what Robyn had said.

Whose way was she talking about? She hadn't said 'my' way, so she hadn't been meaning her own way, or the Cultists.

They already knew the Cultists' long-term goal – to bring Cthulhu back to life. They'd tried to do that by getting the Mechanic to build mechanical body parts for him. But because the Mechanic had barricaded herself away before she'd built a new brain for Cthulhu, that hadn't worked.

What were they going to try now?

After William voiced his thoughts to the group, Nissa said, "The Cultists will likely remain hidden, but they will reveal themselves when they are close to being ready. That will be when you strike."

"Then we'd better make sure we're strong enough to take them on when that happens," Sid said. "There are two things I can think of doing to get us started. The first is that we should check out the Hallow, see what that offers us. The second –" he pulled out a shiny hammer made from white metal, gilded with gold, and a red ruby in the centre – "Is this."

"What is that?" Meg asked.

"Where did you get that from?" William asked at the same time.

"It's named the Pwnhammer," Sid said. "The Wall of Flesh dropped it along with the Firecracker whip I tried to attack Robyn with when she turned. It's labelled that it's strong enough to destroy Crimson Altars."

"Crimson Altars?" William wondered out loud, before he remembered what they were – when they'd first tried venturing into the underground Crimson, they'd found those strange, fleshy masses, covered with piles of eyeballs. They had proven unbreakable, even with bombs, and had even damaged Sid when he'd tried to strike it with his hammer. The only use for them he knew of had been when he'd had to forge his Night's Edge.

"There must be a reason that the Guardian dropped this," Sid said. "And I'm sure it's to give us something for us to become stronger."

"What if it unleashes something even worse?" Meg countered, "What if it accelerates the Crimson, causing it to grow over the whole world in one big swoop?"

"If those altars had that power, we'd already be dead," Sid said.

"I believe it's worth a go," Nissa said.

"It's one of the only things we can try," William muttered.