Thor knew Loki better than Loki would have liked.

So Loki made a point of being utterly unbearable and outright vile to his brother as he was locked in a magically reinforced cell back in Asgard. As soon as they'd removed the gag he flung insults and curses in the general direction of Thor, silver tongue at it's sharpest.

Many people said Thor was too impulsive, that he was easily provoked. Maybe that was true. With anyone else. To be fair, many would have reacted to Loki's general bitterness at this point, crude words about wishing he'd killed him, killed them, killed her, smashed "his precious earth" to dust rather than enslaving "those putrid, pathetic creatures".

Even the guards shared shocked looks, turning to Thor and asking whether they should summon his father. Thor shook his head. The guards were sent back to their posts.

Loki smirked. "Going to punish me yourself, brother? Unshackle me and we'll go for round two. Or is round three by now?"

Thor smiled and shook his head again.

Someone else may have risen to it. Someone else may have yelled back. Someone else may have been disgusted. Someone else may have believed that Loki meant what he said. But then again, Loki never would have said such things to someone else. Whether he realised it or not, Thor didn't know, but Loki only said these things because somewhere deep down he knew that Thor knew.

I know you, brother.

Because despite that what stood before him was six feet two of proud, glaring would-be-conqueror, all Thor could see was the wide-eyed little boy that had followed him around for so many years, trying so, so hard to impress him.