A Promise (An Attack on Titan Fanfic: Erwin Smith)

Prelude

Three inches to the right...

Isanna squinted her eyes in suspicion as she inspected the books on the shelf, arms crossed. She was currently inside Erwin's office (as usual), with the said blond out in a squad leader's meeting.

The grating sound of the door being pushed open caused the raven to whip her head to her right, seeing Erwin step inside the office.

"Why are you still awake?" he asked as he strolled over towards his desk while he took his jacket off and hung it at the back of his chair.

Isanna followed him with her eyes. "I noticed something off with your books."

He lifted an inquisitive brow, waiting for her to elaborate further; he didn't seem to mind the fact that the girl was (unsurprisingly) wearing one of his dress shirts, the clothing overly loose on her torso as it stopped around her thighs.

"This one," she explained, pointing at the rightmost book on the fourth level of the shelf, "moved three inches to the right." She pointed to another book. "And this one is leaning fifteen degrees lower than the last time I saw it."

Erwin's gaze flickered towards his shelf filled books, mildly astounded how she caught on to such subtle changes; her sharp senses never failed to amaze him. However, he wasn't surprised at the fact that some of his belongings have been 'shifted'.

"I'm guessing those guys have been snooping here while no one was around," Isanna remarked, referring to the trio of ex-thugs and realizing that they had already made their move.

"So it seems," Erwin mused, "leave them be. They won't find it either way."

Isanna hummed before she stifled a yawn, signs of drowsiness evident on her face.

Erwin caught on and softly smiled. "It's already late. Go to bed, young lady."

Still yawning, the raven nodded and made her way to the door that led to the room. "I swear, you're the only one who still calls me 'young'."

Erwin was still standing beside his desk as he stacked the files of paper, segregating the documents into their respective categories so that he wouldn't get disorganized while checking them tomorrow morning. A thought crossed him and he looked at the girl, just as she was about to enter his room.

"Leave some room for me."

Isanna cocked a glance over her shoulder. "I always do."

"You take up all the space each time," he pointed out referring to the vast number of times he had to adjust to her in the middle of the night because she'd suddenly either slap or kick him in her sleep; he got used to it, though.

The girl blinked a few times, realizing how she moved a lot in her sleep. "Fine, fine.. I'll stack some pillows between the bed. Is that good for you, sir?"

Erwin returned his attention on the papers as he continued to sift through them. "There's no need for that." Aside from the fact that putting pillows would only take unnecessary space, the blond was aware that she'd still somehow find a way to cross over.

Isanna shrugged her shoulders with a 'suit yourself', before she closed the door. Stretching her arms above her shoulders, the girl threw her figure on the mattress, her weight sinking into the soft cushion as she rolled to the side on her back and stared at the ceiling.

She didn't know how long she was staring and contemplating about life, but it was probably considerably long since she heard the door creaking open.

"You're still awake," she heard Erwin say not as a question but more of a statement.

Isanna's eyes were still glued on the ceiling. "I was thinking about life." She didn't hear a reply from him and could feel his gaze on her for a while, before he walked over to the bathroom.