Empathy
"You can't hide here Sól."
The thin, solemn little boy looked down at the redhead with all of the superiority he could muster and she scowled up at him.
"Why not?" Sól asked crossly, wrinkling up her freckled nose, "I was here first. Besides, this is my tenth birthday party I'm avoiding."
"Well—well, I was going to hide here," he retorted, "And I am a prince of Asgard. You are merely a soldier's daughter."
"A general's," Sól snapped, standing up in the small space between the table and the wall as she threw the curtain previously concealing her aside, "You know that my father Forseti has ridden with your father Odin into many battles"—
He heard female voices in the hallway and Loki's eyes widened. Now they were both exposed. Quick as a flash, he grabbed her wrist and pulled Sól down with him, both of them crawling under the heavy tablecloth and waiting with bated breath. The feet of two women he didn't recognize soon came into view. The pair was chatting idly and paused inside for a moment before walking out and Loki sighed with relief without moving from his position under the table. After a few long seconds of silence he turned and looked at Sól, who was biting her lip and toying with one of her large emerald earrings. Her red hair, usually left free to hang around her shoulders, was pinned up in a severe bun.
"Why are you hiding, anyway? It's your party."
"Doesn't matter," Sól replied darkly, "I don't want everyone staring at me and waiting for me to mess up or worse, going on about how perfect my sister is."
Years later Loki would have a name for the warm feeling of kinship growing inside of him, but for now he didn't, being content to sit beside her and listen to the slow, even sound of her breath beside him.