The Heroes of Olympus: The Demigod Diaries was released on August 14, 2012 and is the companion book to the one of the main series The Heroes of Olympus. Rick Riordan officially announced the book on January 9, 2012 on his blog. His son, Haley Riordan has written his own short story called The Son of Magic in the book.
"What dangers do runaway demigods Luke and Thalia face on their way to Camp Half-Blood? Are Percy and Annabeth up to the task of rescuing stolen goods from a fire-breathing giant who doesn't take kindly to intruders? How exactly are Leo, Piper, and Jason supposed to find a runaway table, dodge a band of party-loving Maenads (who just might be a little psychotic), and stave off a massive explosion... all in one hour or less?"
"With his trademark wit and creativity, Rick Riordan answers these questions and more in three never-before-seen short stories that provide vital back-story to Percy Jackson and The Olympians and The Heroes of Olympus books. Original art, enlightening character interviews and illustrated profiles, puzzles, and a quiz add to the fun in this action-packed collection that is sure to delight legions of loyal fans."
- The Diary of Luke Castellan: A story from Luke Castellan's point of view, from the days when he adventured with Thalia and Annabeth.
- Percy Jackson and the Staff of Hermes: A classic first-person Percy Jackson story, the first Rick Riordan has written since The Last Olympian. In this adventure, Annabeth and Percy's date is interrupted by the god Hermes, whose staff has been stolen by a fire-breathing giant. And what about the snakes George and Martha? This cannot be anticipated as a good thing...
- Leo Valdez and the Quest for Buford: A Leo Valdez story, set at Camp Half-Blood. As Leo builds the Argo II, something goes terribly wrong. Now Leo will need the help of Piper and Jason or the entire camp might be destroyed.
- The Son of Magic: A debut short story from Rick's own son Haley, who inspired the Percy Jackson series. Haley ponders the question: "What happened to the demigods who fought with Kronos' army after the battle in Manhattan?" This is the story of one such demigod. This son of Hecate from Kronos' army finds a mortal ally in his search for redemption. What would it be like to be an outcast? What sort of powers would a son of Hecate have?
The Diary of Luke Castellan
At the beginning, Luke, writing in his diary, chronicles his journey with Thalia from when they found Amaltheia to when they met Annabeth. Luke starts recounting his journey beginning with Amaltheia. He writes that he had run away from his house after his dad, Hermes, and left his mom. He had been traveling with fellow demigod Thalia Grace after they met in the outskirts of Los Angeles in front of a dragon's cave. Luke and Thalia make their way to Richmond, Virginia, in front of a statue of Robert E. Lee, following Amaltheia. Thalia explains that Amaltheia had raised Zeus when he was a baby. Luke questions Amaltheia's motives, but Thalia tells him that the magic goat leads her to good things, adding that Amaltheia led her to Luke, an oblivious comment on her part that makes Luke embarrassed. The goat then indicates for them to enter an old mansion across the street and the demigods head toward it as Amaltheia vanishes.
Thalia asks Luke to do his 'thing', and Luke magically unlocks the door. Once they enter, the door behind them lock, trapping them inside. Thalia tries to escape by a window, but the drapes burn into her hand and try to suffocate her. Luke saves her with his golf club, and voice calls down the stairs and tells the demigods to run. Luke grabs Thalia and they enter the farthest left room up the stairs. There, they meet Halcyon Green, an old man, son of Apollo. Luke notes that there are jail bars separating them from a monster. Hal informs them that the monster is called a Leucrotae, but the monster speaks for him. He says that he was born with the gift of prophecy, but Apollo warned him not to use his power. Hal states that he used his gift to save a young girl's life and she gave him a dagger as thanks. Apollo, however, took away his voice, trapped him in his childhood home, and forced him to wear the skin of Pythos, who use to guard the Oracle of Delphi. A panel in the back opens and two more leucrotae join the first one. Hal tells the demigods that the leucrotae would feast on them by 7:03 pm, at sundown, and he would take their supplies. He continues to explain that the leucrotae can't be killed by any metal.
Thalia tells Hal to send the monsters away, and Hal reluctantly agrees. Luke and Thalia try to figure out a way to escape, but soon give up. Luke is tempted to feed Hal to the drapes but stops himself. Hal types on the computer to tell them that they can read anything they like except his diary. Thalia, frustrated, wonders why Amaltheia led them there. He assumed the two were there for the treasure and leads them to his room. There, he unearths a safe. Luke, using his powers of Hermes, manages to unlock the treasure: a bracelet. Hal exclaims that Apollo told him his curse would end when the owner reclaimed the treasure. Luke tells Hal that he should be able to see if they survive today, but Hal says he can't use his powers again. Thalia exclaims that the treasure must help kill the leucrotae but Hal sadly dismisses the idea. Luke decides to search for ways to kill the leucrotae on the computer, but fails.
Hal decides to read the future and turns to Thalia. He tells her that she'll survive, but sacrifice herself to save her friends, stand tall and still, change once, then change again, be sad and lonely, and find her family again. Hal tells Thalia that he didn't see anything about the bracelet and types that he only knows Amaltheia was slain by Zeus, and her skin was created to make his shield, the Aegis. Thalia exclaims that her future makes no sense and tries to talk Luke out of his turn, but he agrees. Hal stares at Luke in horror and tells him that he saw fire, a sacrifice, a choice, and a betrayal to his friends. Thalia is angered by Luke's prophecy and mocks Hal, but Luke ponders over the word fire. The three then attack the books and Hal finds a recipe for Greek fire. As the hours past, Luke wonders over his prophecy, but decides to focus on the task. Thalia unwires the computer to summon a catalyst. Hal takes Luke to the side and scribbles in his diary. He tells Luke to take the book and that it would help him with his choices. He gives Luke the dagger and offers himself as a sacrifice. Thalia unleashes the lightning and the Greek fire is ready in the jar. At 7:03 pm, the leucrotae start entering the room. Hal takes the jar and lures the monsters into the bathroom.
Luke and Thalia run toward the panel as a leucrotae discovers the ploy. Hal unleashes the Greek fire as the demigods make their way downstairs, sacrificing himself to save them. Luke figures out the code word to activate the bracelet, Aegis. The leucrotae blindly launches itself onto the drapes and is consumed. The house explodes and the demigods wake up back with the statue. The house burns down as sirens echo in the distance. Luke grabs Thalia and they decide to head to the James River and restock on supplies. Luke promises Hal that he would fight back if the gods mistreated him. Nearby, a noise draws the demigods' attention. Luke senses something at Richmond Iron works, and they find Annabeth, who ran away from her home because she wasn't wanted. The demigods decide to take her in, Luke gives Annabeth Hal's dagger, and promises her that he wouldn't fail her like their families had done to them. Back in the present, Luke finishes writing in Hal's, now his, diary while on guard duty. Thalia begins to wake up for her turn and Luke finishes writing.
Percy Jackson and the Staff of Hermes
While celebrating their one month anniversary, Annabeth Chase asks Percy Jackson what he had planned for their special dinner on that night. Percy, who never remembered promising something like that, stalls for time just as Hermes arrives. Percy takes Hermes into his truck to talk, where the god reveals that while he was delivering packages to Janus, Cacus snuck into his truck and stole his caduceus. Because Hermes doesn't want to be seen looking for it, as the other gods would never let him live it down, he sends Annabeth and Percy to find it for him. Annabeth takes out her Video Shield and at first when she said 'Let me see Cacus', the shield shows her the city of Seacacus New Jersey. After she rewords the sentence and finds that the giant Cacus is in the meatpacking district.
When Percy and Annabeth get there, they climb down a ladder into the sewers and find an underground cavern. There they meet Cacus and he tries to sell them watches and clothes, which Annabeth quickly notes are fake. When Percy asks for the caduceus back, Cacus claims he will figure out how it works and become the god of traveling salesmen, mostly by forcing George and Martha to listen to him. Annabeth and Percy go on the attack, with Annabeth stabbing him in the back of the knee and Percy stabbing his leg. However, Cacus backs her and Percy into a corner, destroys Annabeth's shield, and is about to turn her to stone when George and Martha turn into a cell phone. They escape the cavern when Percy calls thousands of gallons of New York sewage to him and it pushes them to the surface, with Annabeth cursing Percy the entire time.
Annabeth then comes up with a plan and runs to a crane, knowing how to operate it as she observed them on Olympus. Percy lures Cacus under the crane's large hook and Annabeth drops it on his head before picking him up and swinging him into the air, where Percy destroys him with the caduceus' Laser Mode. Percy and Annabeth then return the caduceus to Hermes, who is very grateful. When questioned what other enemies the gods have and what exactly Zeus has been threatening, Hermes dodges the question. As a reward however, Hermes transports them to Paris for a special dinner, hence sparing Percy of embarrassment with foods that Percy could not pronounce. Their night ends with Percy and Annabeth walking by the river and Annabeth wondering what Percy has planned for their two month anniversary, which makes Percy happy that she sees a future for them in a month.
Leo Valdez and the Quest for Buford
After two months of working on the Argo II for the battle against Gaea and the Gigantes, Leo Valdez is worried about the camp's safety as the ship threatens to blow up, taking along most of Camp Half-Blood's forest. Jason Grace and Piper McLean soon answer Leo's distress signal and rendezvous with him at Bunker 9. Leo explains that Buford, a temperamental walking table has fled from the cabin after being polished with Windex, taking along two syncopators vital to the ship's creation. Leo then reveals that a mixture of deadly fluids will mix in less than an hour and destroy the woods. Jason and Piper agree to help and the trio head into the forest. Leo then ponders about his seclusion in Bunker 9, instead of enjoying the camp and how fast Christmas has arrived. Jason finds tracks and as the three decide whether it is Buford's or not a naiad tells them to be quiet or her crazy cousins would hear them.
With no choice, the trio press on, soon reaching the site of the Battle of the Labyrinth. Piper than finds Buford heading into the forest, but before Jason follows, Leo orders his friends to hide behind the collapsed boulders of Zeus' Fist. Maenads, followers of Dionysus, soon skip into the clearing and disturb a drakon. Before Jason or Piper could help, the Maenads ask the drakon if it's Dionysus. It answers by attacking, but the Maenads rip the drakon to shreds. They then discover the trio's location and ask Leo the same question. Leo states that he is the wine god, and tries fruitless efforts to escape, but to no avail. Slowly, the Maenads figure out the truth and order their deaths. The three barely manage to escape to the naiad's brook where Piper informs them that they can't kill the Maenads, because they'll be cursed by Dionysus. Leo thinks of a plan and tells Jason to find Buford while he and Piper lead the Maeneds back to Bunker 9.
They reluctantly agree and split up. Leo and Piper successfully lead the Maenads to the bunker. Leo gives Piper a button and she climbs up the catwalks, trying to distract the vicious nymphs. Leo hastily puts together a trap, and sets himself as live bait as the Argo II threatens to explode in under twelve minutes. The Maenads regroup, but before they could attack, Leo tells Piper to push the button, and it unleashes a party, distracting the nymphs. The demigod launches himself onto a disco ball as a golden net, made from Hephaestian netting, traps the Maenads. Piper reunites with Leo as the timer reaches two minutes. Jason soon appears along with Buford and Leo frantically installs the syncopators into the Argo II. He reassures his friends and Buford that the Argo II would not be exploding. Jason and Piper promised Leo that they didn't tell anyone about the quest as Chiron and Argus come to collect the Maenads, informing the three that they had infiltrated Camp Half-Blood a previous time. The two then ship the Maenads off to Atlantic City. Jason, Leo, and Piper then celebrate Christmas Eve with the campers where they propose a toast to their friendship.
Son of Magic
The story opens with Dr. Claymore giving a speech in front of an audience. At the end of his speech, he asks the audience a question, and a boy in the crowd volunteers an answer "Why can't we stop Death?". Dr. Claymore is surprised but he answers the question smartly. Dr. Claymore then ends his speech by announcing his new book. Afterwards, Ms. Lamia, the host of his talk, congratulates Dr. Claymore on the talk's success. Later the boy who asked the question gives him his address, hoping to get an answer to his question. That night, Dr. Claymore gets a mysterious call from the host asking for something the boy gave him. Claymore refuses and hangs up. When Claymore goes to sleep he has a dream vision of the boy talking to his mother and the boy tells his mother that his sister is trying to kill him and he asks for help. His mother refuses to come between the children. Dr. Claymore tries to wake up from his dream but fails, the boy notices Claymore and is surprised. His mother tells him that she brought Claymore there. Claymore demands to wake up so the mother allows Claymore to wake up.
In the morning Claymore dresses up casually but he also puts his 9 millimeter in his pocket, just in case of crazy fans and goes to a coffee shop where Burly Black, the waiter, provides Claymore with his usual. Later the host from the last night's talk shows up and threatens Claymore. Lamia uses the mist to confuse Claymore. Claymore uses his gun on Lamia and he saw that Burly didn't notice the gunfire which he found odd. Lamia proceeds to attack him but Claymore keeps slowing her down by using his gun. Claymore finds out that Lamia is the daughter of Hecate and she is immortal. Claymore takes Burly's truck keys. Lamia burns down the coffee shop with Burly inside by using her spells. Claymore escapes and goes to the boy's address. He finds out that the boy's father was a mistform and the boy's name: Alabaster. Claymore also learned about the world of the gods. Alabaster uses his magic to defend himself and Claymore from Lamia. Alabaster finds out a way to stop Lamia. Claymore gives his life to give Alabaster a chance to stop Lamia. Claymore travels in the River Styx where he is taken away by Hecate and finds out that Alabaster was not able to use his spell on Lamia and defeat her because Hecate didn't want either of her children to die, so Claymore was given a chance to support Alabaster as a Mistform.
Alabaster wakes with a card in his pocket in the form of Claymore, he taps it and gets a Mistform in the form of Claymore. Claymore puts his hand on Alabaster's shoulders and says that they have some research to do.
The Diary of Luke Castellan
The Staff of Hermes
Leo Valdez and the Quest for Buford
Son of Magic
- The book featured an official picture of Thalia.
- Leo sings the Psych theme song when trying to convince the Maenads that he's Dionysus. The lyrics to the song are "I know you know that I'm not telling the truth/I know you know they just don't have any proof".
- This book featured Haley Riordan's first published story.
- This book revealed that Annabeth is the seventh demigod of the Second Great Prophecy.
- Haley Riordan wrote The Son of Magic when he was 16. He is currently 18.
- Given that sunset was at 7:03 PM, The Diary of Luke Castellan could take place sometime in March or September, as these are the only two months when the sun sets at that time.