The Sea of Monsters

The novel begins with Percy dreaming about Grover being hunted by a monster. He wakes on the last day of his 7th grade year, a peaceful year at Meriwether College Prep. There he has become friends with Tyson, a homeless child that the school has taken on as a form of charity. In gym class, during a game of dodgeball, Percy is attacked by a gang of Laestrygonians, but is saved by Tyson and Annabeth, who was on her way back to Camp Half-Blood after having dreams about the Camp in danger. The three take a magical taxi driven by the Graeae to Long Island. Upon reaching the camp, they see a group of campers lead by Clarisse LaRue battling a pair of Colchis bulls. Tyson is granted permission to move past the camp's boundary in order to save Percy once again. It is revealed that he is a baby Cyclops and a half brother of Percy, as he is also a son of Poseidon. An unknown enemy has weakened the protective walls of Camp Half-Blood by poisoning the tree of the demigod Thalia, leaving the campers vulnerable to future monster attacks. Camp counsellor Chiron is accused of poisoning the tree and fired, though the only evidence against him is that his father is Kronos. Before leaving, Chiron notes that only the Golden Fleece could save the camp.

Due to his charm and skill with a sword, Tantalus becomes the new camp counsellor. As a reward for winning the chariot race, Tantalus sends Clarisse LaRue to find the Golden Fleece and forbids anyone else from leaving camp without his permission. After having a talk with the god Hermes about the fate of his son Luke, Percy leaves camp with Annabeth and Tyson to find Grover. With the help of a hippocampus that Tyson names Rainbow, the trio reach the Princess Andromeda, a cruise ship filled with monsters and demigods that have allied with the titan Kronos. On the ship, they are captured by Luke Castellan, and learn that he is working to revive Kronos. The trio narrowly escapes on an emergency lifeboat, and take shelter in a hideout that Annabeth, Thalia, and Luke built as children. There, a hydra finds and attacks them, but they are saved by Clarisse on her ship the CSS Birmingham.

Annabeth, Percy, and Tyson join Clarisse's quest and journey to the Bermuda Triangle (also known as Sea of Monsters). In order to enter the Sea of Monsters, the ship tries to pass between Charybdis and Scylla, who attack and destroy it. It appears that Tyson and Clarisse are killed in action, so Percy and Annabeth board a life raft and head to the nearest island. Like Odysseus, after travelling through the narrow strait that Charybdis and Scylla guarded, the two land on the island of the witch-queen Circe. Realizing she has turned dozens of men into guinea pigs, they escape on the famous Queen Anne’s Revenge, a former pirate ship. Percy and Annabeth pass the Sirens, and Annabeth confesses her insecurities to Percy. They reach the island of Percy's half brother, the cyclops Polyphemus. Before journeying to the centre of the island, Percy and Annabeth meet Grover pretending to be a female cyclops to trick Polyphemus into not eating him. They also learn that Clarisse and Tyson are alive. They find the Golden Fleece and narrowly escape to the mainland while fighting Polyphemus. Percy gives the Golden Fleece to Clarisse as a token of friendship, as it was her quest. She takes a plane to Camp Half-Blood, but the others are soon captured by Luke Castellan. Percy manages to send a message to Camp Half-Blood in which Luke admits to poisoning the tree of Thalia. The elders see their mistake and reinstate Chiron as camp counsellor. When Luke finds out, he challenges Percy to a duel. As Luke was the best swordsman in camp before he left, he wins easily. As Luke is about to finish off Percy and the rest of the group, a group of centaurs called the Party Ponies, led by Chiron, appear and whisk the group to safety. The Golden Fleece is hung on the tree of Thalia, and the tree is cured. However, the Fleece's magic is too strong and resurrects Thalia, providing another possible demigod for the Great Prophecy.

Percy Jackson

The son of Poseidon; a 13-year-old demigod who goes to the island of Polyphemus in the Bermuda Triangle to find Grover and recover the Golden Fleece. He is accompanied by Annabeth and Tyson, his half-brother, on the quest. He is successful in the end; and gives Clarisse the Fleece while he is attacked by Luke on his way to the Camp. However, he and his friends are rescued by Chiron and the Party Ponies.

Annabeth Chase

The daughter of Athena. A demigod who is 13 years old and a friend of Percy. She accompanies him to the island and helps him in his quest by rescuing Percy from Circe's island. Annabeth is injured by Polyphemus and recovers with the help of the Golden Fleece. She accompanies Percy to Camp after Chiron succeeds in rescuing them from the hands of Luke and the Titan army.

Grover Underwood

The guard for Percy given by the gods, a satyr who has been captured by Polyphemus during his search for the wild god Pan. Due to his poor eyesight, Polyphemus mistakes Grover for a female Cyclops. He is rescued by his friends Percy and Annabeth.

Clarisse La Rue

Daughter of Ares who was given the quest of retrieving the Golden Fleece. With the help of Percy and his friends, she is successful in her quest. Percy gives her the Fleece that she takes to Camp Half Blood. Polyphemus wishes to wed her after it is revealed to him that Grover is a male satyr.

Luke Castellan

The main antagonist, now 20; he works for Kronos. He captures Percy and the rest before being thwarted by Chiron and his brethren, the Party Ponies.

Tyson the Cyclops

Percy's half brother; he is initially portrayed as a homeless child before Annabeth helps Percy realize that he is a Cyclops. He accompanies Percy and Annabeth in their quest and befriends a hippocampus whom he names Rainbow. He is very big and has one brown eye. When Clarisse's ship explodes, he is presumed dead until it is learned that he survived due to his immunity to fire.

The Sea of Monsters generally positive reviews with reviewers praising the storyline, the themes and the author's style of writing.[8][9][10] "In a feat worthy of his heroic subjects, Riordan crafts a sequel stronger than his compelling debut," said a Publishers Weekly review.[11] School Library Journal singled out the novel's plot and main character, stating, "Percy is an appealing kid, and the subject of a chilling prophecy may resonate with readers."[9] Child magazine wrote, "Featuring the cliff-hangers and sassy attitude kids loved in The Lightning Thief – plus a surprising new family secret – this outstanding sequel should win over a fresh legion of fans."[12] Children's Literature called the writing extraordinary[12] and added, "This book, sequel to The Lightning Thief, is an amazing mixture of mythology and young adult fiction."[12] Matt Berman, of Common Sense Media, praised the book, saying "The Percy Jackson series continues to be pure fun, with the author doing nearly everything right to produce a book that few kids will be able to resist."[10] Norah Piehl of Kidsreads.com lauded the style of the book, and noted similarities with its prequel.[8] It sold over 100,000 copies in hardcover by the time paperback copies were released in April 2007.[5]

However, Kirkus Reviews was critical of the book, writing, "it's doubtful Percy wouldn't guess Tyson's otherworldly connection immediately after the dodgeball game ... some of the humor will zip over the heads of the target audience" although they added, "Percy's sardonic narration and derring-do would keep the pages turning."[2]

The novel was followed by The Titan's Curse, released on May 1, 2007. In The Titan's Curse, Percy, Grover, Annabeth and Thalia go to a school to recruit two powerful demigods.[28] Like its predecessors, this book was well received and reviewers praised its humorous style and the plot of the story.[29][30]

• Rick Riordan Myth Master at publisher Penguin Books (UK)
• Percy Jackson & the Olympians at publisher Disney-Hyperion Books (US)
• Rick Riordan at the Internet Speculative Fiction Database