The Second Titan War, or the Second Titanomachy, was the conflict between the forces of Olympus and the Titans, which arose when the Titan Lord Kronos attempted to take his revenge on the Olympians for defeating him and sealing him in Tartarus. He was opposed by the Olympians and the demigods of Camp Half-Blood, including Percy Jackson. The plot of the series revolved around Kronos' plans, who hoped to rise from Tartarus and rule the world once more by defeating the gods. There were five major battles over the course of the war; the Battle of the Labyrinth, the Attack on the Princess Andromeda, the Siege of Atlantis, and contemporaneous battles of Mount Othrys and Manhattan. It lasted approximately four years after Luke Castellan stole the Master Bolt and the Helm of Darkness.
The Master Bolt and the Helm of Darkness
Luke Castellan, a son of Hermes, was contacted in his sleep by Kronos, lord of the Titans. The exact nature of this encounter is unknown, but he was eventually convinced to join Kronos' cause out of a desire for revenge against the gods. He was assigned to steal the Master Bolt and the Helm of Darkness, the symbols of Zeus and Hades' power respectively, in order to start a war between the gods.
On a winter camp field trip to Olympus, he made his move. While the other campers and counselors were asleep, Luke entered the throne room and stole the Master Bolt and the Helm of Darkness with little effort, as the Olympians would never believe that anyone was capable of doing so. They later discovered the theft and went to search for the thief. Ares, son of Zeus, was the one that found Luke and disarmed him before taking the two items away from him. However, Kronos spoke to Luke, telling him what to say, and convinced Ares not to return the stolen items as it would lead to a huge war between the Big Three.
Ares was intrigued and delighted at the idea of a war between the gods, and spared Luke, but took the Bolt and the Helm with him. Ares later gave Percy the Master Bolt in disguise, thinking that Percy would unknowingly bring the Bolt to Hades and die in the Underworld. This would result in Zeus and Poseidon being angry at Hades, and Hades would believe that one of them had stolen his Helm of Darkness. When Percy didn't die in the Underworld, Ares tried to kill the demigod himself, but failed and was forced to flee. Percy sent the Helm of Darkness back to Hades by giving it to the Furies, and then returned to Olympus to give Zeus his Master Bolt. Percy explains that Ares was being used and someone else was making plans behind the scenes. Later, he learns that Luke was the one that stole the sacred items under orders from Kronos, his new master. Luke tries to kill Percy with a Pit Scorpion before leaving the camp. Fortunately, Percy is healed in time, but as a result, the entire camp learns of Luke's betrayal.
The Golden Fleece
After his defection, Luke took control of a monster cruise ship called the Princess Andromeda, which served as his base of operations. In order to render Camp Half-Blood defenseless and eliminate a major ally of the Olympians, he poisoned Thalia's Pine Tree with the help of a spy in the camp's ranks. He then tried to steal the Golden Fleece to use in healing Kronos, planning to later "allow" Percy and Annabeth Chase to take it and heal Thalia's tree so Thalia Grace, daughter of Zeus, could be purged from it. Luke did this because Kronos wished to use Thalia to fulfill the prophecy made about a half-blood child of one of the Big Three.
Luke also ensured that Chiron, trainer of heroes, took the fall for the poisoning of the tree, causing him to be discharged from the camp and be replaced by Tantalus. This worked effectively because Chiron was a child of Kronos and Luke knew the Olympians would suspect him over anyone else.
At first, Clarisse La Rue was sent to find the Golden Fleece. Meanwhile, Percy, along with group of allies consisting of Annabeth and Percy's half-brother, the Cyclops Tyson, went to save Grover Underwood from the Cyclops Polyphemus.
Hermes persuaded Percy to go on the quest and guided Annabeth and Tyson to go as well. Hermes told Percy to go onto the Princess Andromeda, hoping that he would meet up with Luke and convince him to stop his assault on the gods. Percy and his allies landed aboard the Princess Andromeda, not knowing of its true nature, and were captured.
During this time, Luke told the two of his plans to use the Golden Fleece to complete Kronos' resurrection and attempted to recruit Percy and Annabeth to his cause (not willing to recruit Tyson as he reminded him of the Cyclops that captured him and Thalia years ago). When the two refused, Luke ordered his bodyguards to feed the trio to a drakon. Percy and the gang escaped through a lifeboat propelled by a wind canister given to him by Hermes.
Luke later intercepted Percy and his friends while they were looking for a boat that they could use to get back to camp. While he was asking Percy for the Fleece in front of a fountain (his army of monsters watching), Percy used the fountain to send an Iris Message, tricking Luke into revealing the fact that Chiron was framed for the poisoning, resulting in Chiron being rehired. Enraged, he ordered Percy and his friends to be killed. Percy convinced Luke to duel him, a moment both had been waiting for a long time. Luke effortlessly defeated Percy, but was prevented from killing the latter when he was knocked into the pool by a boxing glove glued to an arrow. The arrow was shot by Chiron and his family of centaurs who had just then arrived and proceeded to save them. After Percy escaped, Luke's spite and hatred for the son of Poseidon only increases.
Search for the Ophiotaurus
After Thalia's resurrection, Kronos' second in command, Atlas, devised a plan to capture the Ophiotaurus, which would grant the power to destroy Olympus to whomever killed it and sacrificed its entrails to fire. He remembered the Great Prophecy and chose Thalia to be its killer. The attack on Olympus was supposed to happen after Thalia sacrificed the Ophiotaurus.
Luke was assigned to aid Atlas with this. However, Thalia and Luke were childhood friends and romantically attracted to each other, bringing Luke hesitation to carry this mission out. Knowing this, Kronos told Luke that if he didn't succeed in this mission, he would be chosen to be Kronos' host and therefore suffer a fate worse than death.
Some time before his mission in the Labyrinth, Luke journeyed down to the Underworld to perfect his design as Kronos' host. Making his way to the River Styx without being spotted, Luke bathed in the waters, granting him the Curse of Achilles, which made him immune to injury, except in one particular spot.
The first time Luke bathing in the River Styx was hinted at in a nightmare of Percy's, where he carried the sky in a plan to trick Annabeth into holding it after she was captured, which of course succeeded. He and Atlas later used this to their advantage by forcing a captive Artemis hold the sky in her place, and Luke was happy that Annabeth survived. He also convinced Atlas to keep Annabeth alive until the Winter Solstice. It is a certainty that he bathed in the River Styx before this, as he would not have been able to hold the sky otherwise.
Luke was later seen with Atlas when he summoned Skeleton Warriors to hunt down Percy.
Percy, Thalia and Zoë Nightshade, the lieutenant of the Hunters of Artemis at the time, arrive at Mount Othrys, the regrowing fortress of the Titans, where Artemis and Annabeth are held captive. Refusing to have to kill Thalia, Luke attempted to sway her into joining their side. Thalia refused and the two engage in a duel. Their ferocity and power demonstrated was incredible, but Thalia ultimately won the duel, disarming Luke and cornering him against the edge of a cliff (she claimed that she was always able to beat Luke in a duel). Luke continued to goad Thalia, with Annabeth begging her to spare the traitor. As Thalia and Annabeth argued over his fate, Luke attempted to use the opportunity to disarm Thalia, but she kicked him off the cliff, which causes her much guilt later on.
The fall was described as being 50 feet, and Percy believed Luke had died.
Although his broken body was seen by both an approaching army of monsters and Percy, it was later revealed that Luke was still alive. This is because Luke had dived into the River Styx, which made him almost invincible.
After her battle with Luke, Thalia pledged herself to Artemis (though she had previously scorned the offer), in order to stop the prophecy from coming true through her. It is possible she was also thinking of Luke when she made this decision.
Due to his failure to kill the Ophiotaurus, Kronos kept true to his word, assigning Luke as his next host. However, before Kronos would take Luke's body, the latter would aid him in planning an invasion of Camp Half-Blood using the Labyrinth, which had an entrance hidden between two rocks which Percy and Annabeth found while playing a game at Camp Half-Blood.
In order to pass the gladiatorial arena of Antaeus in the Labyrinth, Luke had to assign some of his monsters to fight to the death to please the giant. Then a captive Percy arrives along with Annabeth and Rachel Elizabeth Dare. Percy dares Antaeus, also a son of Poseidon, to fight him. If Percy wins, then him and his friends get released. If Antaeus wins, then they all die. Percy faces off against three opponents, the first is a Dracaena, then Ethan Nakamura, who was defeated with some effort and the giant himself, who was defeated by Percy. As a result, Luke sent his monsters after them, but they escape with the help of Daedalus' hellhound, Mrs. O'Leary.
When the time had come, Luke was somehow put into a trance. Two telekhines, along with Ethan Nakamura, perform a ritual to resurrect Kronos. Percy arrived to stop the ritual, but it is too late. When Ethan pledges allegiance to Kronos, the Titan Lord rose inside Luke's body and was given the reforged weapon, Backbiter, his scythe with which he had used to kill his father Ouranos. However, Percy was rescued by his comrades, notably Rachel, who threw a blue plastic hair brush at Kronos, allowing Percy to get away. Nico di Angelo sealed their survival by summoning a boulder over the fortress where the ritual was performed. This also saved Camp Half-Blood by preventing Kronos from taking part in the Battle of the Labyrinth. Unfortunately, Kronos now knows Nico's secret: he's a child of the Underworld.
A Hero's Death
During the Battle of Manhattan, Luke was completely controlled by Kronos. During this time, Percy learned that when Kronos achieved full power inside of Luke's body, he would burn through and attain his true immortal form, which would mean any mortal that was in the vicinity would be destroyed, and empower the other Titans, giving them ultimate power. To combat this, Percy also bathes in the River Styx as part of Nico's plan.
Kronos made his way to the throne room of the gods with Ethan Nakamura, destroying the city of Olympus as he did so. Meanwhile, Percy, Annabeth, Grover, and Thalia followed closely after. Thalia's legs were trapped under falling debris, saving Annabeth from Hera's curse and the others continued on. Kronos battled them in the throne room when they arrived, but Annabeth was able to catch Luke's attention, reawakening him, if only partially.
Percy convinced Ethan that total destruction was not what his mother, Nemesis, the goddess of revenge would have stood for. Ethan betrayed Kronos and attacked him, unsuccessfully of course, as his sword shattered against Luke's invulnerable body. Several shards lashed back at Ethan and impaled him, and he staggered to the ground. Kronos, now having an internal struggle with Luke, opened a fissure in the floor beneath Ethan, and he tumbled to his end. Kronos continued to batter the trio, getting closer to his ultimate transformation to his original self.
But Annabeth managed to coax Luke back to his own mind. Luke let Percy knock Backbiter into the hearth, where it was destroyed by the goddess Hestia, leaving Luke defenseless. A beaten Annabeth gave Percy her knife, as they both realized that Luke was the true hero of the prophecy. Percy gave the knife to Luke, who stabbed himself in his mortal point, his left shoulder.
Around this same time, Roman Praetor Jason Grace, son of Jupiter, led Camp Jupiter to attack Mount Othrys. As the Romans fought Scythian Dracanae, Jason toppled the black throne of Saturn and destroyed the Titan Krios singlehandedly. This possibly aided Luke in gaining control over his body and helped Camp Half-Blood defeat the Titans in Manhattan.
After the battle, Percy, Annabeth, and Grover looked away from the following explosion and Kronos's fading screams. Luke was left lying on the floor, dying. Annabeth said that he would go to Elysium and Luke replied, "Think … rebirth. Try for three times. Isles of the Blest." Annabeth replied that he always pushed himself too hard. Then Luke asked Annabeth if she loved him, and Annabeth replied that she thought she did but truly thought of him as a brother. Then Luke pleaded to Percy to not let this happen again. With that Luke died just before the gods arrived, after defeating Typhon, thanks to Poseidon returning. In the end he was taken away by the Fates, after being blessed by Hermes, and remembered and honored as a hero by not only Percy, Annabeth, and Grover, but by all.
- Percy Jackson was given the gift of becoming a god, but declined due to his love for his friends and Annabeth Chase, who he was finally able to admit his feelings to. Instead, he requested that the gods claim their children by the age of thirteen and for Camp Half-Blood to construct cabins for the minor gods and Hades, and that the peaceful Titans should be released. He was thinking of Calypso in particular, a kind, beautiful Titan that was confined because of her father Atlas, but all the other peaceful Titans were also released.
- Grover was promoted to become a member of the Council of Cloven Elders by Dionysus, and was deemed a Lord of the Wild. From this, he gained the respect of many nature spirits and the satyrs. He also was coordinating demigod searches with more demigod children being claimed all over the world thanks to Percy's request to the gods.
- Tyson was made a General of the Cyclopes for his bravery in leading the charge against Typhon. He was also had the choice of any weapon he wanted which was a new club to replace the one that was broken in the battle. Zeus said that they would search for the finest club that could be found. (Tyson refers to his club as a stick.)
- Annabeth, as a reward from her mother Athena, was given the opportunity to rebuild Olympus in whatever way she wants as its new architect. Ares, Aphrodite, and Apollo almost immediately asked for numerous statues of themselves everywhere. She was also in charge of the designs for the new cabins at camp.
- Rachel Dare went to Camp Half-Blood and takes in the spirit of the Oracle now that the curse had been lifted as Hades' children have their own cabin and are accepted by the other gods. She immediately revealed the next Great Prophecy, which the Romans had already remembered as the Prophecy of Seven. This will be fulfilled during the Second Giant War.
- After his success at the Battle of Mount Othrys, Jason Grace was raised on a shield by the entire Twelfth Legion and promoted to the rank of praetor. He served as praetor for only two months before he and Percy were exchanged in preparation for the upcoming war with the Gigantes.
- Following the conclusion of the Second Titan War, the protogenos of the earth, Gaea, stirs from her slumber and begins preparing to raise the Gigantes for the Second Giant War.
In the first book, Percy Jackson, son of Poseidon, Annabeth Chase, daughter of Athena, and Grover Underwood, a satyr, embark on a quest to save Percy's mother, who was being held hostage by Hades, and to find the Master Bolt and later, the Helm of Darkness and return them by the Solstice to prevent a war among the gods. The prophecy is:
You shall go west and face the god who has turned,
You shall find what was stolen and see it safely returned.
You shall be betrayed by one who calls you a friend,
And fail to save what matters most in the end.
In book two, Percy, Annabeth and Tyson sneak out of camp to help Clarisse La Rue, a daughter of Ares, find the Golden Fleece and bring it to Camp Half-Blood to save Thalia's Pine Tree, which has been poisoned by Luke Castellan. They also go to save Grover, who was caught by Polyphemus, the Cyclops. They are given this prophecy:
You shall find what you seek and make it your own.
But despair for your life entombed within stone,
And fail without friends, to fly home alone.
The third addition to the series sees Zoë Nightshade, Thalia Grace, Bianca di Angelo, Grover Underwood, and Phoebe (later replaced by Percy) embark together to save Annabeth and Artemis, whom are both being held against their will. The Oracle of Delphi gives them this prophecy:
The Bane of Olympus shows the trail
You shall rise or fall by the ghost king's hand,
The child of Athena's final stand.
Destroy with a hero's final breath,
In the last of the first series, the Great Prophecy is finally revealed to Percy:
Shall reach sixteen against all odds.
A single choice shall end his days,
Olympus to preserve or raze.
To storm or fire the world must fall
An oath to keep with the final breath