Jason Ian Grace is the demigod son of Zeus and the mortal Beryl Grace. He is the younger brother of Thalia Grace, who practically raised him when he was young. When monsters began attacking her, though, she ran away. When she did so, Jason was left to care for his alcoholic and drug addict mother while spiraling out of control.
When he was five-years-old, he found his mother unconscious in bed and called an ambulance. This resulted in her arrest for child endangerment and him being placed in foster care.
For three years, he moved from foster home to foster home before he was placed with the Minsters. The Minsters proved to be the worst placement possible for Jason as the mother of the household, Pamela Minster, routinely hit Jason. For over a year he was stuck there before she went too far and broke a rib. He went to school the next day, unaware of the severity, but was taken to the hospital when he started coughing blood. He was removed from the household when Pamela was arrested.
Two years later, he began attending Yancy Academy as a fifth-grade student. In his class was a boy who was held back a year called Percy Jackson. The two, along with fellow student Grover, became good friends. However, on a field trip to the Metropolitan Museum of Art in March, they were attacked by a Fury. Grover was forced to relocate them to Camp Half-Blood immediately for their own safety. On the way, they were attacked by a pair of dracanae, and Jason killed one. It was this act, which proved his supernatural strength and control over electricity, which revealed him as a Son of Zeus and resulted in his claiming.