Cal's mother was a famous watch-maker, his mother had always been fascinated with time and the ticking clock, which perhaps is how she got the attention of Cal's father. His mother was born in the U.S, but she moved to Asia due to some work problem. That was where Cal's parents met, and where Cal was conceived. He lived with his mother until when he was twelve and his mother was diagnosed with terminal cancer. A year later, Karen Mars died, but she didn't leave Cal all alone. Cal was left to live with his uncle, a former MMA fighter and a trainer. After his mother's departure, his uncle took Cal back to New York, where his uncle currently resided.

Cal was already a problematic child to begin with, he got into fights all the time and he had a nasty mouth, which brought a lot of beatings. It got even worse after his mother's death. His uncle finally taught Cal how to fight, in hopes to steer his niece back to the right path. He mastered almost half a dozen different martial arts in two years. Cal never got into brawls again after that, not by duty, justice or anything of the sort, only because it was boring, and the only fights worth fighting were the ones in the ring with the people that were trained like him. Cal's power began to surface when he was 14. If he concentrate hard enough, he sees everything in almost a slow-motion, and move half a second faster than he originally could. It was a gift that gave him the edge over all his opponents, though it always drained him to the point of exhaustion when he did it.

One night, celebrating the victory of a fight, Cal and his uncle went out. They had taken the turn into a narrow alley where they met a huge man, or at least that was what Cal's uncle saw. Cal saw something else, a disfigured monster with one eye, greasy slimy skin, and terrible breath. It was only until later, Cal discovered that it was a cyclops. Cal did everything he could, but his attacks didn't amount much. Trying to protect his niece, Cal's uncle was smashed to the wall and badly wounded. Just when everything seemed to be lost, a pair of satyr and demigod came to the aid. They disposed of the cyclops quickly, with a sword that was made out of something Cal never saw before. The demigod and satyr pair then explained everything to Cal, how he, himself was also a demigod. After experiencing an attack from a monster, it was hard not to believe. Seeing how his uncle had gotten hurt because of him, and learning that the attacks won't stop, Cal agreed to leave for Camp Half-Blood.