Just a little one shot from an idea that came to me, so far from canon it's ridiculous.
You creep silently in the shadows, a cloak of invisibility shielding your presence.
The tiny Midgard apartment is nothing compared to the glorious finery of the realm eternal, and you scoff to see exactly how small it really is. You open the first door off the hall, and there in the chamber lies your brother, the mortal woman called Jane next to him. They sleep, while Mjolnir hums quietly from its place on the bedroom floor. The mortal will soon make the journey to Asgard, where she will be awarded immortality through Idunn's golden apples. This honor is only bestowed upon those found worthy of Asgard, and that reason is why you're here today.
You shut the door to your brother's bedchamber, and open the next, a short couple of feet down the same hall.
You open the door gingerly, and step inside. On the walls, the soft blue, red and yellow shapes of stars and planets travel in circles, their glow coming from a child's nightlamp on a tall wooden dresser. A huge wooden crib stands in the corner of the room, a towering mural of yggdrasil painted on the wall above. You creep closer to the crib, and look down. Inside, a beautiful little girl sleeps quietly, her golden brown curls spread out against the pale pink sheets.
It was two years ago today that Thor entered your SHIELD isolation cell, and told you that Jane was with child, and you were to be an Uncle. You'd snapped at him, telling him that was highly unlikely as you were not of the house of Odin, and disappeared in a cloud of green smoke, sending the entire organization into a panic. It was the mortal woman, and the child, that turned Thor from foolish individual ... into a man. For that, Odin was to award Jane an eternity with his son.
Curiosity had finally overtaken you - you want to see the people who worked such magic over the arrogant Thor - and that's why you lurk in in the shadows tonight.
Suddenly, the little girl stirs. You quickly check your magic to make sure you are shielded from sight, and step back into the darkness. Tiny hands grasp the railings and the toddler pulls herself up and looks around with eyes the same blue as Thor's. She suddenly looks directly at you and a smile breaks out across her little features.
"NO-KI!" she chirps, in her little voice.
To say you were startled would be an understatement. How?
You check that your spell still remains, and move to another area of the room, assured that the child is not really seeing you. Her eyes follow you.
"NOKI!" she says, shouting this time, banging her little fists on the wooden crib.
You see the golden wisps of magic above her, and are beyond stunned, but suddenly you hear Thor's booming footsteps coming down the hall, an "I'll tend to her Jane," from his lips.
You freeze in the corner of the room as the door opens and Thor steps in, snapping on the bedroom light. His little girl looks over at him expectantly, as he scoops her into his arms and plops himself down on a wooden rocking chair next to the crib.
"Little one, what wakes you yet again at this hour? You must sleep, please," he says tiredly, rocking back and forth in the chair, looking completely worn out.
His daughter points directly at you. "NOKI!" she says, sure of herself.
Thor freezes instantly with his rocking and looks at the corner, then down at his child, a look of pure shock on his face. He squints carefully, attempting to find some sign of you, but then sighs.
"Little one, there is nobody there," he says, stroking her curls.
She cries then, continuing to point and repeat your name in her childish voice, as Thor tells her she must try to sleep, and continues to rock back and forth. Her cries begin to taper off. but her eyesight never leaves yours as her eyes slowly begin to close with the weight of sleep. Thor presses a kiss to the top of her head, and carefully lowers the now sleeping two year old back into the crib before turning and walking slowly to the door.
He snaps off the bedchamber light, but pauses in the doorway. It's so faint you barely hear him, but he looks back at the corner.
"Goodnight brother."