Dan was concerned.

Marcus was not himself. There was no energy there, in that old frame. None of the spirited intensity that Dan had come to associate with the man. Just what had he done to himself while Dan was away?

The pair were still inside the lab, lingering just outside the sealed off area containing the mad scientist's latest work. With a literal hole in reality floating at the center of the room, Dan had every reason to leave that enclosed space. He had dragged the wiry old man out by the ankle, fully expecting to get Judo tossed for his efforts as soon as Marcus woke up.

Much to his surprise, Marcus had stayed asleep right up until they exited the area, when the edge of the door bonked the sleeping scientist on his forehead. Even then, no karate shenanigans were forthcoming. Marcus came to life slowly and with great effort, pulling himself out of his slumber as though it was clinging quicksand. Eyes, fogged with confusion, cracked open and stared at Dan's face. A long moment passed, and Dan's concern only grew. Marcus was just shy of ancient and had been completely isolated; he could've had a stroke and Dan would be none the wiser.

A voice, dry and cracked from disuse, rasped out, "Did you bring the cookies?"

Dan was no longer concerned.

Gnarled hands flailed weakly at Dan's chest, grasping for the small Ziploc bag poking out of his front pocket. With a frustrated sigh, Dan stood up. His hand dipped into his pocket and tossed the bag of cookies just out of reach.

"You can have them if you manage to sit up," Dan stated dryly.

Marcus's groan was caught somewhere between outrage and misery. His voice dissolved into hacking coughs seconds later.

Dan spread his arms wide, helplessly. "I'd like to help, but I can't seem to understand you."

"Unghhh," Marcus replied eloquently. Bony hands fell to the floor and braced. With agonizing slowness, his upper body crept vertical.

Dan watched the show, arms crossed and unamused. Either Marcus was playing up his infirmity solely to mess with Dan, or the old man was truly discombobulated. Neither option was all that appealing.

Marcus finally made it upright, though his ass was still firmly planted on the floor. He peered at his surroundings with bleary confusion. Almost absently, his hand snaked out and retrieved Miss Margaret's bag of cookies. The doctor nibbled at his prize as he visibly struggled to center himself.

Finally, he spoke. "How long was I out?"

Dan shrugged. "How should I know?"

Marcus rocked back slightly at the response. His brow crinkled. "Right. Of course. You... couldn't know."

He glanced around once more. His voice was shaky. "What day is it?"

"Monday," Dan replied, eyeing the doctor curiously. The mad scientist seemed coherent now, and Dan's fears regarding various old-person afflictions were rapidly fading.

Good. Yelling at the old fool would be easier if Dan wasn't worried about him.

Marcus's free hand rubbed at his brow. He groaned softly as he devoured the last of his snack.

"Two days," he muttered to himself. "I slept for two days. Only two days."

"Marcus," Dan interrupted.

The old man showed no signs of hearing him, continuing to mutter, "Only two days," to himself.

"Marcus!" Dan said again, roughly poking his companion's shoulder. There was a time to be delicate, and a time for answers. Now was the latter.

Marcus jerked away, looking up with wild eyes. "Daniel? What is it?"

Dan's face twitched. He took a deep breath, forcing himself to speak evenly. "Are. You. Okay?"

"I—" Marcus paused, then shook his head like a wet dog. "I think so. I um, I'm having trouble focusing at the moment."

"Anything I can help with?" Dan asked, taking a knee beside him.

"No, I... No. I was dreaming is all. Just a sweet dream," his voice trailed off, but this eyes remained in the present.

An odd melancholy surrounded the doctor, but Dan had more pressing matters to consider.

"Marcus, do you remember what you did last week?" Dan asked, allowing some urgency into his tone. "Do you remember what you built?"

"What I built?"

The mad scientist closed his eyes, scrunching up his face in thought. Seconds ticked by, as the old man's eyes roamed vacantly behind shut lids. Suddenly, they shot open. His body followed, surging to its feet. Two bony arms shot into the air in celebration. His voice, triumphant and filled with glee, shouted, "I built it!"

Dan, taking full advantage of the doctor's lingering disorientation, walloped the old man in the back of the head.

"What did you build Marcus?!" he asked, now thoroughly irritated. There was a large and, frankly, terrifying rip in space-time just sitting there not thirty feet away. They were separated from it by nothing more than a few pounds of steel and glass. This was not the time for celebration.

That fact was not reaching Marcus. The older man turned to Dan, excitement evident in his voice. "A window, Daniel! A spyglass into nonexistence!"

"That's not helpfu— Shit!" Dan cursed as Marcus spun in place, found the entrance leading to his invention, and went through the door. Dan's shoes slipped on the tile floor as he fought for traction. His legs pinwheeled wildly but he managed to follow the crazy fool into the room.

Marcus stood in front of the giant lens, arms spread wide. "My greatest creation! A work yet unequaled by mankind!"

Dan came to a stop just inside the isolated area, well within lunging distance of the door. Marcus was acting crazy, and Dan wasn't willing to teleport so close to that crackling gateway to the Other Place. That couldn't possibly end well for him.

The mad scientist turned to Dan, eyes wild and face flushed. "This lens is an anchor! It stabilizes the unreality of the Gap Between Worlds, and renders it visible to the naked eye! With this device, I can study the space between dimensions! I can pierce the veil to other worlds! In time, I might even find a way to visit them!"

Dan took a sharp breath. The implications were not lost on him, despite the science babble. A way to travel dimensions. A way home. It was an incredibly alluring idea.

But not quite enough to distract Daniel from the soft whispers echoing out from Marcus's little anchor.

"Can you turn it off?" he asked, carefully avoiding looking directly at the thing.

"Why would I want to turn it off?" Marcus asked with bewilderment. "It's beautiful!"

Dan chanced a glance at the softly glowing lens, catching sight of mind-bending fractals that almost toppled him off his feet. He slammed his eyes shut.

"I think it's leaking," he stated as calmly as possible.

"That's imposs—" Marcus paused, and Dan cracked open an eye. The doctor was glancing between Daniel and the machine with an expression of understanding.

"That might be possible," the old man amended. He scratched the back of his head awkwardly. "Perhaps we should leave the room."

"Or we could turn it off," Dan suggested once more. He was already turning away, moving towards the exit.

"No, no, best to let it run. I don't know if I'll be able to get it started again, otherwise."

That wouldn't be the worst thing in the world, in Dan's opinion, though he didn't voice the thought.

The pair made their way out of the walled area, and into the winding maze of Mercury's lab. Marcus took the lead, easily guiding Dan through fields of debris and into an area with a small table and minimal clutter. They each took a seat facing the other.

Daniel drummed his fingers on the tabletop. "So. What the fuck, Marcus?"

Marcus clicked his teeth together several times. A grimace crossed his face. "I apologize, Daniel. I seem to have unintentionally put you in a bit of danger."

Dan's hand tightened into a fist.

"Explain," he demanded shortly.

"Well—"

Dan held up a hand. "Start with the Gap. What is it?"

The old man's lip curled uncertainly. "Well... it's self-evident, isn't it? The Gap Between Worlds. It's right there in the name."

"That means absolutely nothing to me," Dan informed him, tightly leashing his growing anger.

"It's the barrier, Daniel! The place you passed through to get to this dimension! The place you fall into whenever you teleport!" Marcus gestured exuberantly, frustrated at Dan's lack of understanding.

"I know all of that, but what the fuck is it?" Dan repeated, just as frustrated.

Marcus fisted a bit of his own hair.

"I have no idea!" He sounded enormously cheerful despite that fact. "I have no idea at all, but it is!"

Dan didn't know what kind of answer he was looking for, but that most certainly was not it.

Marcus must have seen the look of outrage growing on Daniel's face, because he held out both hands defensively. "I can now. That's the point. I had no way to observe it before. I only knew of it. I knew that it existed, and that is all. That still is all. Give me time, Daniel."

"Marcus." Daniel's voice was arctic. "I arrived at the space station today, expecting another round of rigorous studying or brutal sparring. Expecting to be bored to tears or beaten to an inch of my life. Expecting lessons that you convinced me to sit through, because of how woefully unprepared I was to take the risks that I wanted to take. Instead, I arrive to a half-destroyed lab, a hole in reality, and you unconscious!

"After weeks of listening to you preach to me about jumping into things unprepared, about acting without thinking, about living dangerously, can you maybe see why I don't give a shit that you've found something new to study?" The question ended in a bellow, Dan looming over Marcus with both hands planted firmly on the table.

"It's perfectly sa—" Marcus tried, but Daniel slammed his hand down on the table.

BANG!

"IT'S FUCKING WHISPERING, MARCUS!" Dan jabbed a hand in the direction of the lens. "You, by your own admission, created a portal to a dimension that you know nothing about!"

"It's not a portal!" Marcus replied loudly, his own temper fraying. "I told you before, it's just a window! To observe only! It can't interact with the Gap at all!"

"Oh! Great!" Dan laughed hysterically. His hands left the table to better convey his incredulity through gestures. "So you've made a Palantír! Except, you don't know what's on the other end, so it's worse in every conceivable way! Good! There's no possible way for this to end poorly! No sir!"

"There is no danger!" Marcus yelled back. "There can't be!"

That stopped Dan in his tracks. "What do you mean?"

Marcus took a calming breath. "From what little I've been able to understand, there are no... rules, in there. No physics, no reality at all. Only what we bring with us. And, more importantly, what we expect!"

"That makes no sense," Dan replied flatly.

"Not yet perhaps," Marcus said, unable to keep the excitement out of his voice, "and yet it makes perfect sense!"

"It really doesn't."

"Powers originate in the Gap," Marcus continued, growing more excited, more energetic. His hands moved about, gesturing wildly. "They must. It's why every power is different! It's why we could never pin down exact numbers on an upgrade! We thought it was about the pattern of radiation, pulsing it at precise amounts or in some specific order, but we were wrong! It wasn't the patterns that gave us specific powers, it was we who gave specific powers to the patterns!"

He stood up, meeting Daniel's eyes with wild enthusiasm. "Don't you see!? Humans find patterns in everything, it's just our nature! It was our expectations that gave them power! We thought we were right, and so we were right! This is only a hypothesis, of course, but this could be a major breakthrough!"

Dan watched the ranting scientist for a long moment. His anger had faded into weary irritation. He didn't care what Marcus had discovered. He was far more concerned about the utter hypocrisy with which the man had gone about actually doing it.

No danger? The man wouldn't have been unconscious, disoriented, and half-mad upon waking if there had been no danger. He wouldn't be steadfastly ignoring the whispers coming out of his ugly window had that been the case. He wouldn't be acting so... not himself.

Don't muck about with things that you do not fully understand. A central tenet to live by, according to the old man. One that he used to justify just about everything he taught to Daniel. Research, advancement, learning, could not be rushed. Only tragedy lay in that direction.

What kind of person breaks his own rules so blatantly?

"Why were you unconscious?" Dan asked quietly.

Marcus, still mid-explanation, paused. His face turned a shade of red that Dan had never seen before, and he stuttered, "Ah, well, that was a bit of a miscalculation on my part."

Dan sighed. "Of course it was."