A/N: I am going to tell you now – I have not read ANY of the books and I only saw the movie as part of a group thing with my friends from Myth class, so this is based solely on the movie and a little of what I know about mythology, but not much. I hope that it's interesting!
Percy sighed as he walked towards the camp. He had been visiting his mother for the weekend, and heading back towards Camp Half Blood was something he both anticipated and feared. He had asked his mother to let him walk from the road, as he was still trying to get his head around everything that had happened. He was a hero, but he still had a long way to go with his training, and in the past few weeks, he had felt himself becoming more and more distant from his friends and the camp. Luke had been locked up, under constant observation by Chiron and his helpers. Percy still had trouble believing that he had been so betrayed by Luke, but he couldn't help remember what Grover had told him when he first started to learn who he truly was. Trust no one.
Percy's thoughts were interrupted, though, as something slammed into him, knocking him instantly off his feet and to the ground. He let out a dull groan of pain, moving one hand to his hip to check where he had collided with a large rock. He reached into his pocket for his pen, but before he got the chance to extract it, someone came up behind him, hitting him in the head with the same rock he had crashed into. He filled momentarily with fear and helplessness before passing out cold onto the ground.
When Percy awoke, the first thing he was conscious of was his pounding headache. His whole body felt sore, but his head was, by far, the worst. He tried to look around, but thanks to a heavy, black cloth tied over his eyes, he could see nothing but the dark interior of the fabric. He tried to lift a hand to remove the blindfold only to find that his arms had been secured behind his back, each of his wrists bound to the opposite elbow with strong ropes. Another length of rope had been wrapped around his upper arms, binding them tightly to his torso. He quickly discovered that his ankles and legs both above and below the knee were bound together tightly.
"Mmmph!" Percy tried to cry out, but a thick, white rag had been shoved through his mouth, tied securely at the back of his head. He began to pull at the ropes, hoping got use his powers to get himself loose. If there was water anywhere near him, he should be able to summon it and get free, but after several minutes, he felt no closer to getting free. Panic began to set in, and he tried to maneuver his body enough to reach into his pocket for the pen. However, he quickly realized that his jacket, and along with it anything he could have used to escape, had been removed, leaving him shivering in jeans and a t-shirt as he rested against the cold, stone ground of his prison.
He tried to keep a rational mind, but his head was still throbbing and his thoughts were shrouded with panic and pain. He struggled more, trying to scream for help against his gag. After several minutes, he still felt no change in the security of the restraints, and he gave up, breathing deeply as he curled up on the floor, hesitantly submitting himself to his captivity.