The Story of Halo; How Master Chief came to be.

Cannons boomed holding off the enemy. Soldiers, thousands of them, making a chorus of gunfire into the smoke. 
"They don't want us getting out of earth with these kids," A women said. She was advanced in her years. She wore a white lab coat, had blue eyes, with short grey hair.
"You got that right!" A man said leading the woman,"Just like old times, eh, Dr Halsey?" She gave no reply but continued to follow the man protecting her while she carried a boy over her shoulder, unconscious.
He was about 13, ginger, blue eyes. He was going to be tested on. He was hunted by aliens, called the covenant. They wanted to kill all humans, but this boy seemed different.
Dr. Halsey and Sgt. Johnson, the man escorting Halsey barely escaped with their lives. The boy was named john and was tested on continuously. He was 'augmented' with unbelievable strength. He had memories of the covenant. Destroying Reach, the planet where the new recruits went to train.
John went on fighting covenant with various weapons, his armor with a build in shield, and his AI companion, Cortana.