Dr. Frederick Chase is the American and Military History professor at West Point, as well as one of the few mortals who can see through the Mist. He is the mortal father of Greek demigod, Annabeth Chase and her half brothers, Bobby Chase and Matthew Chase, as well as the husband to Mrs. Chase. He is also the brother of Randolph and Natalie Chase, and the uncle of Emma, Aubrey, and Magnus Chase.
Frederick was the younger brother of Randolph and Natalie Chase. He lived in the Chase family mansion in Boston, Massachusetts (which Randolph would later inherit) during his childhood. Despite this, Frederick didn't enough money to go to college during his youth, despite his brilliant mind and desire to learn. However, his brilliance and wit gained the attention of Athena, the goddess of wisdom, who helped him get into Harvard University. He finished his studies successfully with her help. Frederick's friendship with Athena eventually turned into a platonic romance, which ended on good terms.
Athena sent Frederick their demigod daughter, Annabeth. She was considered a "brain child" like all other children of Athena, which means that they were born from the thoughts of the goddess. The two women appeared on his doorstep in a golden cradle carried down from Olympus by Zephyros, the West Wind. Frederick originally wanted Athena to take Annabeth back, but she sternly told him that demigods must be raised by their mortal parent. Five years later, Frederick subsequently married an Asian woman and had two sons: Bobby and Matthew. When Annabeth was seven years old, Frederick visited his siblings during Thanksgiving. The three Chase siblings ended up getting into an argument, resulting in Frederick and Annabeth leaving, with him never visiting or speaking to his siblings since.
Due to Annabeth being a demigod, Frederick's family was frequently attacked by monsters. As revealed in The Mark of Athena, his daughter was once assaulted by a flood of spiders at night and would subsequently scream for her father, who always seemed to be away for work. Instead, his wife thought his daughter was making it up every time and refused to call him; because whenever Mrs. Chase came into Annabeth's bedroom, the spiders would hide. As a result, Annabeth ran away from home at the young age of seven shortly after Frederick's quarrel with his siblings, thinking that her mortal family resented her the attacks. She later made it to Camp Half-Blood with the help of Thalia Grace, Luke Castellan, and Grover Underwood. From camp, Annabeth would talk to her father mostly in letter form, as phones were too dangerous for a demigod. Mr. Chase would occasionally ask her to return home, but Annabeth always refused.
Annabeth eventually returned home at her father's request, but left when she saw that nothing had changed. Her father then sent her his Harvard college ring, in hopes that she would remember him by it, and be convinced to come home. She started to wear his ring on her necklace with the beads that she earned every year at Camp Half-Blood.
Annabeth accompanied Percy Jackson and Thalia Grace to assist Grover with two new demigods (Nico di Angelo and Bianca di Angelo) at a military school. Annabeth told Percy that her father was moving to San Francisco, but that she was unsure whether to go because the area contained the Titan base of Mount Othrys, and was therefore thriving with monsters. During the mission, Annabeth went missing and Percy went on a quest to save the goddess Artemis to find her.
In San Francisco, Thalia suggested they visit Frederick Chase for transportation. The revelation of his daughter's disappearance shocked Dr. Chase, who agreed to give the questers his car, which they unintentionally destroyed. After rescuing Artemis, the group were gravely endangered by a fleet of monsters, but Dr. Chase flew in on his plane - a Sopwith Camel - ignoring the warnings given to stay away. Using special bullets he created out of some of Annabeth's Celestial Bronze weapons, he shot and destroyed several members of Luke's monster army, ensuring that the demigods would escape. He also saw Blackjack, Guido and Porkpie without any difficulty and questioned how the Pegasi could fly with their body mass v.s. wing span ratio.
At the end, Frederick was relieved that his daughter was safe and reminded her she still had a home with him just before Annabeth left with Percy and Thalia on some pegasi.
Percy thinks of Dr. Chase when he and Annabeth are alone in Athena's Cabin.
Annabeth remembers the time she used to hate her mortal family, and says it was stupid of her to think that way for so long. She then remembered her uncle and cousin living in Boston, whom she hadn't seen for eleven years, due to her father not getting along with his brother after a quarrel.
Eleven years after his quarrel with his siblings, Fredrick and Annabeth are looking for his sister's son, Magnus, after being contacted by Randolph that Magnus has been missing for two years since his mother's death. After Magnus' funeral, Frederick flies back to San Francisco.
Fredrick was mentioned when Magnus was looking at a picture of him and his siblings.
Magnus states that Fredrick was contacted by his brother's lawyer after Randolph died.
Frederick is a fairly normal mortal, though with a genius-level intellect. He most likely caught Athena's attention by his fascination with wars and his love for airplanes. Percy Jackson once described Dr. Chase as an "excellent mad scientist" because of his experiment with Celestial Bronze bullets.
Frederick loves his daughter Annabeth very much and tries to be on good terms with her, though he didn't want her at first. This is somewhat expected, since he didn't know that his relationship with Athena would result in a brain child and didn't have enough time to take care of her, as he wasn't originally prepared. When she ran away at the age of seven, Frederick was heartbroken until her return several years later.
Frederick is described as a handsome, athletic, middle-aged man. He had intense brown eyes and sandy-colored hair, like that of his daughter.
Frederick's elder brother, with whom he hasn't spoken with after their family quarrel 11 years before The Sword of Summer. However, Frederick still cares somewhat for his brother, reconnecting with Randolph and traveled to Boston with Annabeth after learning of Natalie's death and Magnus' disappearance. .
Frederick's late sister, with whom he hasn't spoken with after their family quarrel 11 years before The Sword of Summer. However, Frederick likely still cared for his sister, travelling to Boston with Annabeth after learning of Natalie's death and Magnus' disappearance. He was described by Annabeth as devastated at Magnus' funeral, likely indicating that he has some degree of regret for falling out with Natalie and never getting the chance to reconcile their feud.
Frederick's daughter with Athena goddess of wisdom, warfare and crafts. He was surprised that he had an infant daughter to care for and tried to get Athena to take her back, but she sternly told him that demigods must be raised by their mortal parent. Still, Frederick loves Annabeth despite he didn't pass too much time together in her childhood. His family was attacked by monsters due to her daughter being a demigod, so she eventually thought that her mortal family resented her for this and ran away. This action broke his heart, so the next he saw her, Frederick gave Annabeth his university so she would remember him and might return to their home. When the Sirens sang to Annabeth, she saw her father and her mother together again and happy.
In The Titan's Curse, it seems Frederick's relationship with Annabeth is getting better. By The Last Olympian she seems to be living with their family again, though, this isn't for certain because she is going to go to a school in New York near Percy's, and her family lives in San Francisco. By the events of The Mark of Athena, the two pass more time together and learnt more about each other, including his "sappy side."
Frederick's twins sons with his wife. Though he doesn't pay attention to Bobby and Matthew while at work, they care for each other.
Frederick's brilliance and wit drew the attention of Athena, the goddess of wisdom. She helped him get into college and he finished his studies successfully with her help. Their friendship eventually turned into a platonic romance, which ended on good terms. As mentioned in The House of Hades, years later, Frederick confessed to their daughter that he stil loves Athena. According to Annabeth, "he had looked so sad and defeated, wishing for something he knew was impossible."
His wife and his twins' mother, whom he married when Annabeth was five. The two love each other very much. She didn't mind being the bad cop in raising the children.
- Frederick is the only known male mortal who can see through the Mist.
- Frederick has Swedish Ancestry, being a descendant of Swedish royalty.
- He is the only Chase sibling to have no apparent connection with the Norse Pantheon.
- Frederick is the only Chase sibling to still be alive.
- He also is the only Chase sibling whose children are still technically alive.
- According to Percy, Frederick "plays with toy soldiers". In other words, he makes models of WWI battles. However, it is said that he sometimes play with them, making the shooting, explosion sound effects and other things along the line of that.
- He is interested in collecting war souvenirs, such as his Sopwith Camel biplanes from World War.
- Frederick is currently the only mortal parent of the main (and mortal) protagonists in the Riordan franchise that is both alive and never suffered any type of horrible fate or form of captivity.
- His favorite movie is the romantic comedy "Roman Holiday" from the 1940s and '50. According to Annabeth, it reminds her father of his own romance with Athena.
- Thus he is the only mortal male in the series with the possible ability to see through the Mist in the Greek/Roman books. Amir also has this ability in the Magnus Chase series, though unlike Frederick this ability was not something he was naturally born with.
- Frederick was at one point a professor at West Point and teaches American and Military History.
- Both Frederick and his brother Randolph were both history professors at one point in their lives.