Thor looked at him, beseeching and searching for answers with his eyes. Answers that would not be given, as Loki made no further acknowledgement, only sitting on the meager thing called a bed within the prison cell. There was no reaction even as the telltale slam and jingle of keys signaled the beginning of imprisonment. The guards left the room, and Thor, after another glance, too left.
When Thor's thumping footsteps could be heard no more, it was then that Loki leaned back, stretching out his aching muscles. He left an inaudible sigh, frowning as he assessed the situation. His mouth still held that wretched muzzle, his arms likewise restrained, and he was a bit exhausted. Not to mention his foreboding trial. Not that it was needed, as all of nine realms saw him guilty.
Either way, there was no time. He must make haste, as he had no doubt the first of the guards would be arriving in less than ten minutes- not that he needed that long. Inspecting the lock and committing every detail to memory, it took less than a few seconds for Loki to locate the weak point. A small burst of magic and….there.
Careful not to accidently take off the manacles now in case any guards decided to come early (which he doubted, as Aesir were lazy, but would rather not take the chance), Loki slowly reached for the muzzle. As expected, this piece of technology was far more complex than the handcuffs. Thin, elegant fingers ghosted over all the accessible areas of the muzzle. Loki would've smiled, had he remembered how to do so. Stark was an intelligent man, he had to give him that, but there was no machine without flaws. Magic, though, he thought with vindictive pleasure, had no such things. Lightly applying pressure on the control center of the muzzle (he actually hadn't expected it to be right under the left ear), it took a few minutes for his godly strength to come through. The entire muzzle broke off with a loud CRACK!
Loki proceeded to dispose of the manacles (his inter-dimensional pocket really did come in handy), but he purposely left the muzzle (track device included) on the bed- after any and all traces of magic (fingerprints included) were gone, of course. Then he proceeded to morph. Long and pale fingers turned dark, small and furry, with sharp claws at the ends. Ragged, dirty hair blended into the skin to create a mass of fur. Soon enough, a graceful feline stood in the place of a man. But it too soon disappeared.
Loki couldn't help but purr at the feeling of traveling between the roots of Yggdrasil, walking along the path that only he had ever walked upon. It was so thrilling, the dark masses surrounding the path writhing and twisting, clawing for any purchase it can grasp- anything else to doom the practical nonexistence it exists in. And Loki pounced and twirled and batted, enjoying the semblance of a long lost game he no longer played.
It was through these masses that Loki crept, destination couldn't have mattered less.