Out of the hundreds of scenarios Loki played out in his mind to escape the dungeons, only three seemed even remotely plausible.
The first scheme was too precarious to even consider: Loki could create an illusion that he was extremely ill, perhaps replicate the symptoms of a highly feared sickness, and act as if he was near death. If he was fortunate, a guard would believe the ruse and inform Odin of Loki's condition. However, Odin would likely see through the hoax, thus destroying Loki's chances of ever escaping. The more depressing scenario was that Odin may order the guard to let the illness take Loki's life. After all, it would be one less execution the All-Father would need to worry about. But the chance that Odin would actually be concerned enough to send a healer for Loki's "illness" was too small of a probability to risk it. Besides, even if the plan did work, Loki was sure there would be dozens of guards to happily stop him before he managed to even reach the stairs.
The second strategy was slightly less absurd, but also far too blandly predictable for Loki to actually consider: When the guard brought him a meal and briefly opened a small translucent door on the side of the cell, Loki could grab the guard's arm and refuse to let go until the door was fully opened. This, however, was also extremely hazardous because the guard could shout for help. As a result, Loki would be trusted even less and the amount of guards would undoubtedly triple in number. In addition, if he actually managed to escape his cell, Loki would not get far until he was met with guards. He could easily overpower an army of them, even without a weapon, but the noise would surely bring Odin to their rescue, and Loki to a swift execution.
The third plan was the most likely one to succeed, but it would unquestionably cost Loki his pride: It would take weeks, perhaps even months, to slowly "show guilt" for his crimes. Of course, it would be nothing but a skillfully calculated act, but it would require Loki to gradually have an "emotional breakdown". But Loki knew that if he seemed genuine, Thor would fall for it. Eventually, Loki would be released by Thor's insistence and would simply continue the 'I feel guilty' act until he could gain everyone's trust. He would be on his best behavior to ease the kingdom's worry. Then, when the occasion presented itself, Loki would find a way to become King of Asgard. As brilliant as the plan seemed, it would not only kill his ego and crush his wicked reputation, but would also take a year or more to carry out.
Loki didn't want to wait a year to become King. He wanted it now.
I should not have to wait for a throne that is rightfully mine, he thought, grinding his teeth.
Something moved in the corner of his eye, interrupting his train of thought. Loki's heart clenched in hope for a moment, going against his mind; he knew he shouldn't hope for anything, for doing so caused him nothing but frustration and disappointment. And he immediately felt both of those things as he realized the moving figure was nothing of importance; only a guard.
Loki watched the heavily armored man march through the dungeon and nearly scoffed as the guard dared to meet his glare. You should be kneeling before me and quivering in fear, you pathetic cur, Loki wanted to growl at the man, who was still staring.
Loki rolled his eyes. How idiotic, he thought. But then a humorous idea came to him. From the comfortable position on his bed, Loki raised a finger and suddenly cast an illusion of himself standing close to the cell wall and grinning madly at the onlooker. The guard actually squeaked in surprise and jumped away from the startling illusion, eyes widening and then quickly looking away to stare at the floor.
Loki couldn't help but chuckle, a mischievous smile growing on his face. He may have been locked away in a dungeon to prevent any more wars, but no one could stop him from endlessly taunting those who guarded him. The soldiers had it coming, though. They were always glancing warily at him, unease written plainly on their faces. They observed Loki as if he was an animal. Perhaps I am, Loki considered, grinning as the guard marched past and avoided looking up again. Good, Loki thought with swelling pride.
There were very few people that did not cower in Loki's presence, most of them being Thor, Odin, and his mother, Frigga. But without fail, every time someone passed Loki, they'd nearly shudder in fear, despite the fact that he was inside an impenetrable cell. It was practically impossible that Loki could escape, and yet those in his presence still felt tremendous anxiety. And with good reason, too; even as he sat in the dungeons, he was still Loki, a powerful magician and a Prince of Asgard.
He was still a Prince, too, no matter what Odin thought. And perhaps not today, or even the next thirty days, but eventually, Loki would be King.
This is just a random drabble I wrote while trying to get into Loki's character. Hope you guys liked it! :)