Thalia Grace is the daughter of Zeus and Beryl Grace, a TV starlet the god met in the 1980s. She was born on December 22, 1987, 7 years earlier than her brother Jason. In The Lost Hero she is revealed to be the older sister of Jason Grace.  Due to her mother's abusive nature, Thalia has considered leaving home since she was little, but stays to protect Jason from her mother's antics. However, when Jason is apparently killed during a visit to Sonoma (in actuality, he is merely presented to Hera), Thalia finally runs away at age 10 and stays with Luke and Annabeth until they meet Grover Underwood when she is 12. When the party reaches Camp Half-Blood, Thalia gives her life to hold off pursuing monsters on top of what would later be called Half-Blood Hill. To save Thalia's life, her father transforms her into a pine tree. Her spirit then provides a magical barrier that protects the camp until seven years later when it is purged from the pine tree by the Golden Fleece .
After the double-murder suicide, former wrestler Christopher Nowinski contacted Benoit's father, suggesting that years of trauma to his son's brain may have led to his actions. Tests were conducted on Benoit's brain by Julian Bailes, the head of neurosurgery at West Virginia University, and results showed that "Benoit's brain was so severely damaged it resembled the brain of an 85-year-old Alzheimer's patient." He was reported to have had an advanced form of dementia, similar to the brains of four retired NFL players who had suffered multiple concussions, sank into depression, and harmed themselves or others. Bailes and his colleagues concluded that repeated concussions can lead to dementia, which can contribute to severe behavioral problems.