Title: A Shadow in the Back of my Mind

Summary: The nightmare's not over. With a shadow now taking up residence in Jack's dreams, can the Guardians destroy the darkness before Jack falls under?

Rating: T (later chapters)

A/N: Saw the movie and I have headcanons pouring out my ass. I obviously took some liberties with my headcanons in this story, including how Jack dreams/sleeps. Woo~

I obviously don't own anything.

Chapter 1: Numb

Jack Frost often dreamed in white. Icicles hung from his imagination and snow flurries buried his subconscious, bathing his dreams and thoughts in blizzards. This was how it had been since as long as he could remember, the cold that permeated his body becoming a comfort and a reminder of his immortality as his dreams swirled like snowflakes behind his eyes.

Against what children may believe, even the immortals needed their rest, and Jack loved sleeping; more importantly, he loved to dream. Before he became a Guardian, dreaming was a time when he could forget his loneliness and be surrounded by things and people that he didn't necessarily recognize but felt loved with. He would sun bathe and feel warmth in a way he couldn't as a winter spirit and swim with dolphins in water as shockingly blue as his eyes.

Jack was highly in tune with his dreams, to a point that even Sandy was impressed. The Sandman would often drop by to check on the sleeping spirit when he buried himself in blankets of snow in a secluded room in North's factory, always wondering how Jack managed to create a perfect dream world without help from the spirit of dreams.

And because Jack was so aware of what happened when he was asleep, he noticed immediately when something was wrong. What should have been an expanse of white in his mind was dimmed, and he felt a pulling at the back of his subconscious. Curiously, Jack made a full turn, whatever dream he had been happening falling away and quickly forgotten in exchange for discovering what this sensation was. It felt like pins and needles- a numbness that still managed to hurt.

He shifted uncomfortably and took a step back, gasping when he tripped over something behind his foot. Jack's staff was in his hands in a moment and he used it to catch himself. The boy turned to look at the ground but noticed it was nothing but a flat area of white. Tilting his head, Jack knelt down and ran his hands along the smooth floor. A spark of something caught his eye and he turned, spotting a dark spot in the distance of his mind. Getting up, Jack took off running after it and then pulled himself into the air to shoot after the diminishing darkness.

It was a while before Jack realized he wasn't getting any closer to the sensation. The thing hadn't moved, but apparently neither had he. Even as he hung, suspended, in the air he expected the darkness to recede but it stayed when it was. Jack awoke to thoughts of confusion.

That was the first morning that Jack woke up tired in a long, long while. Not thinking anything of it, Jack left his bed and went on with his day, eyeing a small town in Northern Virginia to give them an impromptu snow day in the middle of the high schools' finals week.

/ / /

That night while Jack slept, he fidgeted uncomfortably from underneath his snow drifts, the icy edges scattering around the bed when he kicked at them.

In his dream, Jack took a startled step backwards. The sensation had returned, and it was stronger. Jack wondered how it had happened, but the dark shadows reached their tendril further in front of itself and seemed to reach for him. Jack stood and watched the rolling movements of the tendrils, transfixed, as one reached out and caught him around the ankle. The arm pulled and brought Jack to fall onto his back. Jack, suddenly scared, let out a gasp and kicked at the arm.

The darkness didn't release him, and the shadow tightened his grip, growing more solid. Jack grit his teeth as sudden numbness shot up his leg and his staff was suddenly in his hand. Bringing the wood down onto the tendril, the blackness seemed to shriek at the contact before releasing Jack's leg and retreating back to its corner.

Jack closed his eyes and took an even breath before finally asking, "What?" aloud. Reaching a hand down he ran it along the length of his calf, rubbing it to remove the numbing tingles that pulsed through it, nervousness and adrenaline pumping through him. This was the first time Jack wished he could wake up.

Jack's eyes snapped open in the slowly lightening room. He had kicked his covers off some time in the night and he then reached down to tug them back up around his body. There he lay until the sun was shining a little brighter through the window and only then did he drag himself out of bed, rubbing his eyes and yawning.

When he stepped out of bed, his right leg gave out and he sent himself crashing to the floor, eliciting a quiet noise of surprise from him. Righting himself, Jack inspected his leg to notice a bruising along the area that the shadow arm had wrapped itself around.

Running a hand through his silver hair, idly watching snow drift down from the shaken strands, Jack closed his eyes. "What's going on?"

/ / /

It was North that eventually started noticing the change in Jack's demeanor, mostly because the jolly man was around most often. He first noticed it when he saw Jack gently push one of the elves out of the way instead of slicking the floor with ice and watching the poor thing tumble its way down the hall. As Jack dragged- dragged!- his staff down the hall after him, North stood up from his study and followed the winter spirit down the hallway.

The Russian Guardian watched as Jack tiredly pulled himself up onto one of the windowsills, pushing the glass open to let in a gust of bone chillingly cold wind. North let out a harrumph and stalked over to the boy.

"Ah, Jack." He began and Jack startled slightly, looking over his shoulder at the larger Guardian.

"Oh. North." He said before turning back to the window.

North furrowed his brow, "Jack. Why are you here and not out spreading winter? Why are you not out causing snow fights and sending the children and their families falling down sidewalks with ice? Hm?"

Jack let out a soft laugh, though it sounded more like an exhausted sigh. "I'm not feeling like it. Let them have a nice day for once. Is that so hard for me to do?" Jack leaned his head back against the wall, closing his eyes as a snow flurry found its way through the cracked window.

North tugged his jacket a little tighter, wondering what to ask this boy that North has taken such a paternal fondness to. "Are you eating all right, then?" Jack nodded so North continued to try and diagnose the problem. "You are not sick?" Jack shook his head. "You are sleeping comfortably?" This time Jack paused before shrugging his shoulder and North nodded.

"Very well. You will spend your day how you wish, but tonight we will tuck you into bed and you will drink warm milk. If it is trouble sleeping, I can help." North laughed and Jack gave him a tired smile.

That night Jack sat on the edge of his bed, bare toes idly drawing circles in the fallen snow on his floor, as he watched North carry in a tray of something. As the Guardian set the tray down, Jack inspected the platter, finding a cup of steaming milk along with a plate of cookies.

"These help?" He asked skeptically and North nodded.

"It is how I prepare for sleep every night!" He said, sounding proud of the fact.

Jack snorted and rolled his eyes, but was so exhausted and still concerned about the just now fading numbness of his leg that he figured he'd give it a shot. Taking a purple frosted cookie off the plate and the mug in his other hand, Jack downed both within a minute before putting the cup back. North looked pleased when Jack flopped backwards onto his bed and with a flick of his wrist dragged the snow from the floor up and on top of him.

"Thanks." He mumbled sheepishly when North stepped forward and tucked the edges of the drift around Jack's body.

"Of course. You will sleep well now, like me. I will see you in the morning, Jack. Sleep well." North gave his goodnight and gathered up the tray, popping a cookie in his own mouth.

That night Jack dreamt of dark arms ripping the ground out from beneath him and he woke to the sensation of falling forever, surprised to feel cold trails of dried tears at the corners of his face.