He appears in The Lightning Thief, The Sea of Monsters, The Titan's Curse, The Battle of the Labyrinth, The Last Olympian, The Son of Neptune, The House of Hades, The Blood of Olympus, The Burning Maze, The Chalice of the Gods and Wrath of the Triple Goddess.
In The Heroes of Olympus series, Grover mainly appears as one of Camp Half-Blood's satyr allies reporting on Gaea's rising and participating in negotiations with the Romans to get Reyna to help transport the Athena Parthenos statue across the world.
She appears in The Lightning Thief, The Sea of Monsters, The Titan's Curse, The Battle of the Labyrinth, The Last Olympian, The Lost Hero, The Demigod Diaries, The Mark of Athena, The House of Hades, The Blood of Olympus, The Chalice of the Gods and Wrath of the Triple Goddess.
He later participates in the battle with Nero's automaton and gives the resurrected Leo Valdez a kick in the gut—joining the campers who literally line up to hit Leo—for scaring him with his sacrifice to destroy Gaea.
She is seven years older than her brother Jason Grace and appears in The Lightning Thief, The Sea of Monsters, The Titan's Curse, The Last Olympian, The Lost Hero, The Blood of Olympus, The Dark Prophecy, and The Tyrant's Tomb.
Due to her own bad experiences with Cyclopes, Annabeth reluctantly takes Tyson with them to Camp Half-Blood where his immunity to fire proves to be vital in defeating the attacking Colchis Bulls.
After the battle, Tyson and Ella rename the bookstore Cyclops Books and provide Apollo and Meg with the first part of a new prophecy that directs them to return to New York City to face Nero.
He appears in The Titan's Curse, The Battle of the Labyrinth, The Last Olympian, The Son of Neptune, The Mark of Athena, The House of Hades, The Blood of Olympus, The Hidden Oracle, The Tower of Nero and The Sun and the Star, of which he is one of two main protagonists (the second being his boyfriend, Will Solace.)
Following the loss of Delphi to Python, as revealed in The Hidden Oracle, Rachel stops visiting camp and begins a frenzied attempt to regain her foresight, not helped by Apollo's disappearance.
In The Blood of Olympus, Will attends a head counselor meeting discussing the situation with Romans where he laments that he lacks the combat skills of many of his siblings due to his gifts being for healing.
Will delivers Coach Hedge's baby boy Chuck and, despite not being a fighter, volunteers to join the team sent to scout out the Roman positions to get a break along with Lou Ellen and Cecil.
In The Sun and the Star, two months after receiving their prophecy, Nico and Will are the last kids at camp after all of the other demigods, including the year-rounders, choose to leave to see the world or to be with their mortal families at the end of the summer.
Rachel arrives to repeat her prophecy for what turns out to be the twelfth time and Nico convinces a reluctant Chiron to give him and Will an official quest to rescue Bob.
At the end of The Dark Prophecy, Calypso stays at the Waystation, while Leo goes to warn Camp Jupiter of an impending invasion and Apollo travels with Meg to search for the Erythraean Sybil.
Reyna is often accompanied by two magical dogs, Aurum and Argentum, or by her pegasus Scipio ("Skippy" dies after their trip from New York to Greece in The House of Hades after being slashed by a griffin's poisonous claw).
In The Heroes of Olympus, Apollo's Roman descendant Octavian promises the god many things for blessing his prophetic skills, which leads to the Olympians' distraction from the true threat of Gaia, and to the resurgence of Python.
Nero taught her the arts of a demigod and gave her a pair of crescent rings which can transform into sickles made of imperial gold, before giving her a task to lure Apollo into the Grove of Dodona.
Unlike Carter, Sadie is rebellious and bold and acts the part; often making snap decisions, ignoring rules, and choosing to wear clothing to display her personality (such as combat boots) rather than to conform or aid her magic.
Walt eventually admits to Carter that Anubis thinks he only has until the next day's sunset to live and that the god has been helping him to make sense of his strange new power to turn things to dust.
After Set's defeat, Desjardins is outraged that Carter and Sadie chose to make a deal with the god rather than banish, but chooses not to attack them in the end, realizing that enough fighting has been done for one day and that his men appear to be wavering after witnessing the Kanes give up the powers of Horus and Isis willingly.
In The Red Pyramid, Julius Kane uses the Rosetta Stone to release Osiris and return him to his throne in the Underworld as a first step towards restoring the gods due to the increasing threat of Apophis.
Goaded by his demon minion Face of Horror, Set decides to summon a storm that will destroy North America at sunrise on his birthday to increase his own power.
Set insists that he is simply a necessary evil, balancing out the other gods who are good and that he does not want Apophis to win, reminding Carter of his service as Ra's faithful lieutenant.
Sadie nevertheless completes the spell, taking the final beetle of Khepri's form and releasing Apophis who possesses Menshikov to fight the Kanes directly, proving to be more than a match for them.
However, as a god, Apophis can't be killed by the spell which only destroys Menshikov and banishes the serpent a little deeper into the Duat, buying the Kanes time to escape with Ra.
After defeating the rebel magicians, Carter calls upon the gods to join the battle, but even together they prove to be no match for Apophis who kills Nekhbet and swallows Ra, darkening the sun.
In Demigods & Magicians, Setne begins using hybrid Greek-Egyptian magic from the Book of Thoth, repeatedly drawing the attention of the Kanes, Percy Jackson and Annabeth Chase to stop him.
In the Brooklyn House Magician's Manual, Setne is shown plotting to escape after his prison is accidentally cracked by one of Sadie's spells after which he intends to take the Book of Thoth, travel into the Duat and finally become a god.
A 16-year-old Bostonian teenager, Magnus lost his mother Natalie Chase to a mysterious wolf attack two years prior to the events of The Sword of Summer and is forced to live in the streets with his homeless friends, Blitz and Hearth.
He is skinny with pale skin and with short spiky blond hair, which, when combined with his black leather jacket, jeans, and a candy cane scarf, "makes him look like a character from a Japanese anime".