There are places made to be forgotten. The deep, abandoned, underground where everything fell in the Mushroom Kingdom embodied this clearly. Piled cadavers along the rockface where spillover of bones and other decayed remains occurred every few hundred feet. Untended soil, hard as cold steel, promised an abrupt end for anyone who failed to jump across even a narrow gap.

"Have you ever thought of guardrails?" the Doctor tried counting how many bodies there were but kept losing the number to keep her lunch down. "Or bridges, I love those. The way they can be long or short, but always make you feel like you're invited to cross. How does anyone survive grocery shopping if they skip leg day?"

Luigi had been quiet for a while, the Time Lord decided one-sided conversations were more productive than listening to death's silent chorus. Quite disturbing, when things are so quiet that one's own heartbeats boom like bombs in the dark. To her surprise, and relief, the Plumber found his voice.

"We use the pipes." The blunt tone in his voice became understandable when they passed an obscuring pile of bones. A massive wall of lime-colored steel appeared, stretching on for miles, woven into the land to be as eternal as air. Seeing its rounder shape, the Doctor confirmed for herself that this indeed was not standard house plumbing.

"Are these what you work on, because I'd raise your rates."

She ran a hand along the pipe, surprised at its warmth. Luigi did the same, closing his eyes as if in prayer.

"They were made long, long ago, guided by willpower," Luigi explained. "You stand on top of it, or alongside an opening, and focus on seeking the other side. They each lead one place, not always somewhere friendly. Some use signs to highlight a destination, others Mario and I recognize through experience."

The Time Lord watched the Plumber with growing admiration, when her eye caught something peculiar.

"Say, Luigi, would anyone try sabotaging these pipes?"

He looked as if she uttered the unholiest blasphemy.

"Never," he stated. "Even Bowser knows to respect them. A single disruption would damage the lives of millions."

"I think that's the intent for whomever did this."

Pulling her hand away, the Doctor revealed a jagged green scar. There were no burns or metal fragments to imply a tool had been used. Miming the pattern with her index finger, the Doctor pieced together a theory.

"Someone's figuring out how to misbehave with your plumbing."

The Doctor used her sonic screwdriver to seek any remaining evidence. An electronic signal traveled up to the Time Lord's mind, decoded into comprehensive data. She received a diagnostic, not metal yet heated to an intense degree, but the energy output was interesting. Especially how similar reading resonated two hundred feet away.

"Got the signal," she said. "Let's get our shift on."

They charged off, guided by the jagged frequency towards very immediate danger. The possibility of survival depending on a vacuum cleaner came to mind as the Doctor noticed a sickly green spark. She noticed where the pipe had been dug up, as if by many hands. Claws, the Doctor corrected herself while looking closer, some of the diggers were missing fingers.

Her hand froze an inch from a polished patch of dirt, barley two feet of space that had been smoothed over. Recognizing what to look for, she saw twenty similar spot ahead… and thirty behind them. The Doctor lifted her head to speak but froze.

Barely an inch of movement, yet she felt it.

"RUN!"

A Koopa's skull burst from the dirt, almost chomping off the Doctor's hand as she pulled it back. Bone claws shot up, slashing for flesh. Luigi yelped as he barely dodged the ambushing skeletons. Grabbing his arm, the Doctor hauled them towards a gap within the minefield of reanimated deceased. Evading thrashing dirt-crusted limbs became harder as more attackers closed ranks to block their escape. Surrounded, the dead started to march forward, hollow eyes beckoning the two living souls towards a cruel end.

That's when the Doctor heard a vacuum come to life. While nothing implied this as the moment the tide turned, there was a confidence in Luigi's stance that could not be ignored. Nozzle raised, the Plumber activated an intense drag of air into his device. A nearby attacker's bones rattled under the pull until Its head became trapped on the device's mouth. With impressive strength, Luigi hefted the whole skeleton, slamming it into skulls, toppling them over like dominos. The Doctor wondered how much force could be exerted to create such a grip and quickly got her answer as Luigi switched to reverse. Their unwilling ally shot out like a cannon, smashing into Its bony kin. They now had an opening to leave.

"I think you'd be better off a cleaner than a plumber." The Doctor said as they charged free of peril.

"Maybe," Luigi used a hidden plunger on the device to grab one skeleton and break up pursuit by jamming them together. "I did manage to buy a mansion cleaning up a haunted house once." He did not seem fond of remembering that time, but the Time Lord could not deny look of pride in the slim Plumber's eyes. "What's our next move?"

"That's the good thing about traps, bad people usually set them up when you're getting close to where the evil plan is happening."

They followed the pipe, which far larger than anticipated as the ground turned into a steep hill. The green spark became blinding, only several feet away now. Not wishing to make an introduction without more detail, the Doctor and Luigi moved further away. They found a nearby patch of upturned dirt, close enough to see who was making the spark.

Most of their appearance was hidden behind a white cloak but the Doctor could see a pale hand holding a strange stone dagger. Energy erupted around it when making contact with the pipe. Without proper symbol or insignia, the Doctor had no possible way to identify their affiliation. However, the screwdriver did not lie. The signal thread Gideon had picked up, it echoed from this strange tool. The cuts from earlier and the current damage confirmed what was being done.

This troublemaker was trying to break open the pipe. Close inspection of the skeletons earlier implied they were reanimated with some strange formula. It carried a pathogen which the Time Lord guessed must have been what resulted in Mario's strange injuries. Jars of the concoction were nearby, prepared to be released when the pipe was burst open.

"Say, Luigi, where does this pipe lead?"

The Plumber peered over the hill, then pressed his hand against the dirt. The gloved fingers curled as Luigi's eyes were closed in concentration. A green light radiated from the L on his cap. The connection was severed when he released the ground, coming to life and trembling with terror.

"Oh no," Luigi said, "She's trying to break into a secret pipe, that'll spread this poison through Worlds 3,4,and 5. A whole quarter of the Kingdom will be overrun!"

The Doctor was about to try and calm him down when a greater question surfaced.

"Wait, she?"

The explanation came much sooner than hoped, almost taking off her head. A lack of welding helped the Time Lord duck violet shaded fireball.

"Very perceptive, Plumber," a cold voice said. "It is a shame your brother failed to consider better caution. Bumbling down here, some nasty bites should be expected when one dares to be so intrusive." Luigi's raged blazed but cooled with the Doctor's hand. Anger was only good when directed at something precise, she needed more data to get a proper target. Time for a conversation.

They stood up, no point in hiding, looking out at the woman in white and her skeleton army. The army formed a menacing semi-circle which grew every moment with gap narrowing. Soon, an attack wouldn't need to be ordered for both heroes to be swarmed. The Doctor stepped forward, one hand held back, signaling to wait.

"Awfully rude of you," the Doctor said, as if speaking to one and not an army. "Speaking poorly of the injured without looking someone in the eye."

The woman chuckled.

"I would not wish to frighten."

"Let me decide what's worth being scared over," the Doctor said. "It's hard enough to see anything down here, in the dark."

The woman laughed loudly, gripping her hood with both hands. Pulling it back, what was shown shook both hearts.

"Sight has been lost for so long it was barely a memory."

A bald head, where the black tattoo covered the woman's head, the clawed hand gripping her skull. Milky blank eyes reflected the Doctor's growing shock. Their entire demeanor expressed too much stolen to properly function yet driven by an unseen force which compensated in nightmarish ways. The Timelord witnessed enemy and grim promises of what the future held in one dangerous foe.

"Don't worry, it didn't hurt." She said. "And things are far clearer now. The beat of your hearts is… curious. No disgust… concern? Even knowing I've barely started to be a true terror, Doctor?"

"Letting go of the light does not mean it cannot be found," the Timelord said. "What is your name?"

The woman's smirk soured.

"Names were abandoned, even longer than sight, Doctor. I am a Helper of He who is Awake. When the tasks are done, what use would anything be in oblivion?"

"So that's what this is about," the Doctor said. "All these clacking bones, manipulated through the dagger like a remote control? Seems a tad noisy for the end of everything."

"This is just the beginning, experimenting with how best to bring out…" Helper stopped, grinning bittersweetly. "Quite clever, getting me to brag and possibly find a way to squirm stubbornly against the inevitable."

"Well, everyone loves a monologue, gives plenty of info, Helper."

The woman raised her dagger. It cackled with flames as the skeletons turned more volatile, moving forward with lurching steps.

"What little scraps were found shall be consumed in this val—"

"Luigi, get the knife."

The vacuum came to life in an instant. Soil kicked up behind her boots, and the Doctor smiled. Luigi had found a smart use of his anger. Sensing the flow stop, she quickly jumped aside as Luigi fired large clumps of mud and dirt at the army. While not the most egregious projectile, a massive clump of grounded up soil can quite effective. Especially when fired out of a vacuum cleaner with the force of cannon fire. Everything struck stumbled under a brutally abrupt reburial. Helper suffered the worst of it, but managed to claw to the surface, knife in hand. While aiming to do something possibly fatal, a plunger head zipped in and plucked the weapon away. Luigi tossed the dagger to the Doctor, who used her sonic screwdriver to compete with whatever strange frequency compelled this reanimation. When the attackers froze things looked better, then turned splendid as the skeletons crumbled into bony heaps, many quickly covered by soil.

The Helper remained submerged up to her waist, showing no sign of retaliating. Luigi helped the Doctor to siphon some of the poison, scanning it to seek an antidote for Mario and many others who could possibly have been afflicted. Yet the Timelord knew this skirmish could not count as any proper victory.

"Quite a dodgy bit of craftwork, this thing," the Doctor eyed the knife while kneeling down to face the Helper. "Tuned to affect bodies where life had once been present. Gives off a wicked kick of energy, I'm curious how someone makes something this powerful on their own. How many Helpers does it take to make a zombie dagger? Ten? Twenty? Did you take lunch breaks?"

"Do you intend to annoy me into submission?"

"Well, you're not going anywhere, and my Plumber friend is heading back to fix up all your vile actions. All it took was making a quick call to the locals above to drop down a feather. Brilliant stuff, this Kingdom."

"Why don't you stop playing cute, and be honest, Doctor, or are you afraid to know my answer?"

The Helper finally smiled as Doctor's enthusiasm faded to her true demeanor, calculated and determined.

"Where is He who is Awake?"

"Afraid to speak the Devil's name?"

"I've met plenty of gods and devils in my travels, nothing stands out too much to give any one credit above the rest."

"HAVE YOU REALLY?!"

Pulling back the mask made it easier for the Time Lord not to be so easily rattled. Even as the Helper laughed maniacally. Unable to properly move, only twist about, and the Doctor still had to resist the urge to back away.

"Almighty Timelord of Gallifrey, seen all and faced the worst with a smile. Never choosing to accept the common fear of what lies in the dark. Choosing to look at the deepest horror with a meek shrug. Even when standing in His Presence."

"Because he remembers you, Doctor. Remembers how you managed to look at the ultimate foe, yet bemused himself with the idea that you managed to look him with eyes shut from the truth. Too proud to accept something bigger, older, after some many centuries growing big in arrogance inside that blue box. He does recognize your progress, Doctor, but where you have needed to grow the Devil simply is."

The Doctor leaned in.

"You've spoken with him, so there is direct contact."

The Helper grimaced.

"Monologues, got me again."

"I've already figured out you're from my splash of a universe. All I need is a bit more to get a time and place."

All expressions faded from the Helper's face.

"And then what, Doctor?"

She leaned in until their faces were inches apart.

"Hop in your Tardis and charge in? Could you truly make that leap? Seek Him intentionally and think that would lead to anything but doom?"

"You saw that darkness, the same as me. Tell me, after looking at it, was there any choice but to accept you'll be consumed?"

There was no sound. The ground around the Helper abruptly swallowed her whole. No screams and yet the Doctor knew she would never see this woman again.

It took five minutes to move away, to turn her head, from that patch of dirt. Walking to the Tardis was harder than it should have been. No dead disturbed her, she wished something familiar or known would show up to be a problem. Getting to the console, typing in coordinates of the recent infestation showed significant progress in the search, but also highlighted how the journey was far from over.

Hand hovering over the switch that would lead to some new destination, the Doctor wondered despite her best efforts. She started to consider what it would mean to face something that would always be beyond anything her prowess could face. The end, of her and everything she cherished. That result could not be learned, only discovered by peering over the ledge, hoping to be wrong. With one way to find out, the Doctor flipped the switch and took the plunge.