Action continues as leo is sent to Ogygia, Calypso's islnad, and as Percy and Annebeth have to survive in tartarus also as Jason and the Argonauts II find thenselves in the middle of africa thanks to a wind bomb that was placed on the Argo II , and are stuck since the Argo II is in bad state and its creator Leo, is absent . They soon find themselves in the hands of the god of the southern wind Notus or Auster(roman form) , who in his best day is crazy and lazy as hell. They stay some days reparing ( or as much as they can since they don't know a thing about mechanics), and he supposely sends spirits to help, but they are just lazy at their best day, finally one day Jason snapps and goes to make him decide a form and finally help them, but instead he tells him he will give him horses, wind horses, who are the fastest of the southern wind, but as he changes back and forth from Auster and Notus the horses change from storm to fire skinned beasts. He decleras that he shall decide his legacy, and Jason picks the greek , for wich will be both excellent consequences, but some dark too. 

Meanwhile Leo is getting depressed because he just has his Archimede's shephere, and still needs materials, but his mood changes to happiness when he finds... celestial bronze, the metal that his father uses, he thanks Hepheastus and goes to work in a boat, after days Calypso finally goes to lecture about how she doesnt want noise in her home, when Gaia appears... She promises freedom to Calypso in exchange of Leos life, and Leo is like "Damm, its a win win for them " "but is astonishly proved wrong as Calypso banishes Gaia out of her home, and Leo no matter how cant seem to understand that, how could she give freedom for him, who he hated. She later explains that, if she wanted so badly for him to die, it was because she was afraid of him, then they start taking like for each other as they both start constucting a boat so that he can get back to his ship.They still have a week for the launch day, but Leo is now having his doubts about leaving as every hour passes he is liking more Calypso, who equaly returns the feeling. And thats when the magic boat appears and thakes him back to the world.

As they are led towards Damasen's hut in the swamp, they are intercepted by a huge Medean Drakon, who is Immortal unless Damasen or another giant kills it, and when they are about to be chicken roast , Damasen appears, he uses a huge tree and impales it ont the drakon's mouth. He greets them in a weird way as if sad to see them, he lets them stay on his home, and the next day tells them that only one person can help them go unnoticed towards the doors of death... the midnight lady, who uses the grief mist , powerful enough so that monsters or even the giants cant sense them. Annebeth tries to convincd him , that he should acompany them, the prophecy says it, but Damasens refuses, for its his destiny and punishemnt to stay there and everyday kill that drakon for eternity. Annebeth for more that she tries does not convince him, and goes upset towards the death cliffs. Percy , Bob, and Annebeth continue their path until Bob says its time to part ways, that he cant go to the death mist, for he is not the same type of creature as the demigods, the sadly leave him and continue their way. Once they meet the midnight lady, she lets them think they tricked her into helping them, but reality is she tricks them , for once you're of the deathmist almost nothing can bring you back. Then she takes them to the edge of the highest peak where she plans to sacrifice them to their mother Night or better known as Nyx, who is one of the eldest beings in the Universe.


Meanwhile back at normal earth, they are asaulted by some dwarfs, who in the end fall to their side, and are sent by Leo valdez to make chaos on the roman camps that are advancing towards his home : Camp Half-Blood. Later they are assaulted again, but this time by the snow goddess and the Boreas, who fall to Leos creation the metal dragon. Who is brung back to life by Piper's charmspeak, but this assault leaves a big crack on both the Argo II and on the team, for Leo was sucker punched into a place were Hione knows he wont be able to comeback... Calypso's Island, for the gods as punishment send her heroes she will fall in love with, but heroes who are neeeded and already in love like the case of Ulysses(Odysseus) who loved Penelope, but in this case Leo is not her type, so he wont be able to go.

Three days , its what it took them to getr there, at least one problem was solved now there was someone to close the doors of death from inside , the problem was they were just two against a gazilliion enemies. 

As they are going to fall they see that the most possible thing its that the are going to be sqashed against the floor, but because percy can control water, they make the river Cocytus cushion their fall, the problem is that , its the river of lamentation, and they almost die there.

After they are out they realize what truly a prison Tartarus is , they air is poisonous and burns the skin, but they still continue, they feel they cant stop , until they see that their skin is starting to blister, then Annabeth decides to take the risk of drinking of the river Phlegethon the river of fire, that keeps creatures alive, but in suffering, so they continue walking, feeling better when they see a group of Empousai (Greek vampire like demons) and decide to follow them after haring that they too are heading for the doors of death, when they have to climb down they veer off the path, and are ambushed by them, and as they are going to be killed... (SPOILER) The Titan Iapetus (renamed Bob after percy submerged him in the river Lethe he lost his memory and came over to the good side) falls from Hade's realm and kills the empousia with his double edged lance (wich was converted into a mop, sice the jerk of Hades used him for a Janitor) and happily goes with them, he guides them through everywhere, and takes them to Herme's altar wich he explains must have falled down. Then they continue their path pressured because Polybotes and Hyperion the titan (archenemies of percy feel their scent) and run to a swamp where they meet Damasen the only good Giant.

This book like the other ones of the heroes of olympus is written in second person because it describes like someone was seeing it, and its not omnicsient . After Annabeth defeated Aracne ( Spider goddess , hates Athena and her children). She is grabbed by her webs and when Percy (son of poseidon) tries to help her they both go down to  Tartarus...
Then the story shifts to Hazels story , where they are trying to cross the alpines but the Ourae ( Greek mountain gods wont let them pass, so she's sleeping when suddenly the titaness of magic Hecate appears to her and offers help, and a great cost. She has to learn to control the mist ( The mist makes humans see what they want to , because no one wants to see monsters and giants, they wont see them) and is warned that she is going to have to battle her best apprentice, who betrayed her to Gaia's side.

I chose it because... This was the series that made me a reader, i have read all of the eight books of percy jackson, and sincerly i really like them, because it is based on greek mythology, wich i love, also this author writes real fact like they were opinions. He also wrote a similar series called the Kane chronicles , wich is of egyptian mithology . This is the book number nine of the series and maybe the last one,  when finally I will learn the outcome, if Percy dies or if Gaea and the titans loose.