Loki was quickly learning that he required less sleep than most mortals. This place was silent during sleep cycles, as a rule - there were a few active minds buzzing about, of course, but overall the entire ship seemed to settle into a stale sort of quiet that made Loki restless. He had little to exert his energy on in this place, and thus he was already wound tighter than perhaps necessary - but the silence and the lack of activity made it even more pronounced.
Thus, most evenings found him prowling the halls. Tonight his gait was agitated, almost agressive - he had spent far too long lost in his own thoughts, yet he had nowhere else to be lost. He had been tempted to seek out Elsa, but she likely needed ordinary amounts of sleep - and as fantastic as her powers were, and as much as he would like to use helping her hone them as a distraction from his frustration at the dead ends he kept hitting in his attempts to find a way home, it was likely best that he not disturb her.
The figure in the hall ahead of him was familiar, and set Loki's stance from agitated to guarded immediately. Natasha. She was not among his favorite people on board this ship; their previous encounter had not exactly gone swimmingly. Anyone who wished to manipulate him was an enemy, no matter their motivations - anyone who preyed upon his weakness, his lack of knowledge about what led him to a future as a villain bent on destroying a harmless world - anyone like that was not someone Loki intended to trust with a single breath.
As he neared her, he offered merely a steely-faced nod of greeting - he was not going to be completely rude, after all - but said nothing, content to simply continue walking.