All I can say is: "Finally!" I have waited for this book for a whole year, The Heroes of Olympus being one of my favorite series ever I have read each and every book multiple times. This one though, the epic conclusion, ripped my heart out and stomped on it. Ugh, I still cannot believe it's over, I have eagerly awaited the next book in the series for the past three years, always something to look forward to and obsess about as the date looms nearer, I still cannot believe it is over. (The Feels,) okay time for the actual review now.(SPOILERS!)Rick Riordan likes to mess with his fans, by leaving misleading clues around social media and tweeting things that makes us go insane waiting for the book. You will never, ever, ever in a million years be able to predict what Mr. Riordan has in store for us. For example, if someone said they predicted Percy and Annabeth falling into Tartarus in The Mark Of Athena I can say that you are a big liar. I'm also sure no one predicted Bob the Titan would come back from the original Percy Jackson and the Olympians series. Anyway, I had no idea what Mr. Riordan would throw at us and I personally did not want to guess.When I first got the book in the mail I was super excited, rushing upstairs immediately to read it. I was flipping through the book when I realized that the only characters that had POV's were Reyna, Nico, Jason, Piper and Leo. I was not very happy, Throughout the whole series I've hated Reyna for acting too strongly as Praetor and almost getting Annabeth killed in The Mark Of Athena. Nico, I do like better but honestly I would have been more happy with a Percy or Annabeth chapter. Jason and Piper, are the lowest of the low for most of the series, they do nothing really except in the first book, but Piper changes a lot in this one. The only POV I was really happy about was Leo's he is one of my all time favorite character's from any book ever.So the book begins with Jason's POV (grumbles.) Apparently, Hazel disguised Jason, Piper and Annabeth using the mist. Jason typically complains about his new form as an old man, claiming he was useless in battle. So we have about thirty-forty pages of them introducing the story and Jason walking into an area with a ton of ghosts who want to kill him. Now he is finally happy about Hazel's trickery with The Mist. Anyway, eventually his form comes back and they have this battle until a ghost of his mother comes out, who abandons him as a child. She asks Jason to stay with her and help the ghosts but he quickly says no, even though so much conflict was rolling through him at the moment. when they were about to leave Jason gets stabbed by someone with Imperial Gold who says "Born a Roman, die a Roman." Imperial Gold is very deadly to demigods and it's really unlikely he would survive, but Piper and Annabeth get him back on the ship and now Jason just has to fight for his life.The POV switches to Reyna, throughout this book I have so much more appreciation for Reyna, she is now a desirable and strong character. She abandoned Rome to stop a war between the Greeks and Romans. Now Octavian, a ruthless, dictator-like praetor rules, obsessed with killing all the Greek demigods, for what purpose I do not know. So she has to deliver The Athena Parthenos, I giant statue Annabeth got in The Mark Of Athena. Nico, who I need to give a lot more credit to, and Coach Hedge, a funny, kung-fu obsessed Satyr have to get the statue to Camp Half Blood to stop the war. Nico is doing the most work, he has to shadow travel and transport all of his friends and a giant statue halfway across the world a bit at a time. But every time he uses underworld magic, since it's so exhausting he deteriorates a little. At one point he become see through so that he can walk through objects but he still accepts what he has to do. Nico probably works the hardest through this entire book for more than just that reason.Leo, is busy on the Argo II fixing up stuff and trying to figure out how to get back to Calypso. He had to leave her in the last book when he was stranded on her island, his goal is to become the first person ever to return.Throughout this book Nico, Reyna, and Coach Hedge run across Orion, who tries to kill Reyna, her sister Hylla who is Queen of the Amazons and who she runs into, and Artemis's hunters. As they transport the statue he is always a major threat and towards the end of the story Reyna finally kills Orion after the Athena Parthenos and her mother, The Roman Goddess of war Bellona grants her powers. Afterwards Nico, Reyna and Hedge arrive at Camp Half Blood and defend themselves, while trying to get the statue in place in time. While this is happening even more is going on with Jason, Piper, Leo, Hazel, Frank, Annabeth and Percy.Before the climax the seven of them got into a fair amount of battles. One of which happened with Percy's sister and a giant. They won because when Jason promised Percy's sister who is a goddess more honor they all teamed up on the giant and defeated him. After that Jason's wound inflicted by Imperial Gold magically healed even though he had been on a death bed before.I'm going to skip over the numerous battles, in which Leo formed a dangerous plan, they got a formula that could raise someone from the dead, and victories and go to the climax because it was super important and this review is way too long. So at first Piper, Annabeth and Percy are the only ones fighting the giants and trying to prevent Gaea from rising. Gaea would only rise if the blood of a female and male demigod would soak into the earth, which is currently under their feet. Piper had watched hopeless and Percy and Annabeth were being attacked. Piper was very underestimated being the daughter of Aphrodite but that's a huge mistake. Piper stalled the giants for a while, trying to keep Percy and Annabeth alive until she chopped off the hand of one of them and they dropped Annabeth. Annabeth was already injured so she couldn't help a few drops of her blood soaking into the earth beneath her. Percy was freed soon after, but he wasn't as hurt so no blood soaked into the earth.The three of them battled and tried to hold their ground for a while until Jason, Leo, Frank, and Hazel came down from the Argo II and fought with them. To kill a giant you need the help of a god so at the moment they were just trying to defend themselves. Percy was very careful not to let a drop of his blood hit the soil beneath him but during a battle it was practically impossible. He didn't notice a drop of blood rol of his chin and hit the soil beneath him, that was when Gaea woke, she could kill everyone, she had control of the entire world's ground.Nico, Will (a child of Apollo), and Reyna were battling the Romans when Gaea rose and the ground shifted and a voice echoed through the air. That was undoubtedly Gaea threatening them all. Despite the fact that the statue had been placed Octavion still wanted to kill them all.With the seven half bloods the battle was slowly dwindling. They couldn't hold off that many giants, then the gods came down to help them kill the giants. It took a little while got eventually they killed each one of the giants and they knew they had to get to Camp Half Blood, because Gaea was still awake.Upon arrival Leo stayed in the ship with the formula to bring someone back to life, he knew his plan was the only alternative. The rest of them fought, the Romans were no longer fighting the Greeks and the Greeks were no longer fighting the Romans, they both teamed up on the monsters that were coming in.That was when Gaea got full strength, she morphed into the figure of a person made from earth and grass, Leo's crazy, original plan finally went in action."FOOOOMP! In a flash of bronze, Gaea was swept of the hillside, snarled in the claws of the fifty ton metal dragon."Leo had fixed Festus, his metal dragon and now the ground solidified for the time being. Jason who could fly took Piper up and they tried to defeat Gaea. The three of them tried to put Gaea back to sleep but in the end it was Piper, who went through so much extensive character development who did it. She used her charmspeak to put Gaea back to sleep, but they were still far from done.Here's when the sad stuff starts. Leo ordered Jason and Piper back to the ground, they hesitantly obliged, then Leo put the final part of his plan into action. He blew up Festus, he died and Gaea was put to rest.Leo died, the jokester, the trickster, one of my favorite character's ever, died to save everyone. Leo who had built the Argo II to bring everyone along the quest to safety died, at the time I realized he would never be able to find Calypso.Back on the ground, I wasn't really paying attention, I was too distraught, but I believe Nico allowed Octavion to kill himself, which I am frankly happy about and then the war was over.The Aftermath:A few days later everyone was still grieving. Leo was gone, no one could believe it. Hazel and Frank returned to Camp Jupiter with Reyna and Nico, son of Hades, who never had friends, who never thought he belonged anywhere, wandered aimlessly. Until Will, who Nico was sure he was avoiding, asked him why he wouldn't visit a friend. Nico was stunned that someone regarded him as a friend and he was so pleased that instead of wandering around aimlessly, pushing people away, and not belonging anywhere, he decided to stay.Percy and Annabeth were going to spend senior year together and then go to college in New Rome. Piper and Jason were fine at Camp Half Blood, but still mourning Leo, who had been their friend before they had found out they were demigods. Coach Hedge and his wife Mellie had a baby named Chuck who was just as crazy as the Coach.Just as I was finishing the book, I was shocked to find the last chapter in the POV of Leo. Leo was funny and witty as usual and apparently he had escaped death using the formula, (yay, but it wasn't a great ending nonetheless.) Festus and Leo descended upon Calypso's island where he would stay forever. He had yelled in glee over coming back to life, but his friends would never know he was alive, he would never see them again. He arrived at Calypso's island, and the series ended with Leo and Calypso riding off, on Festus the metal dragon's back.(I still can't believe that 10 book series is over, I'm really sad.)Easter Egg:But there is an easter egg we will learn more about in 2015. Annabeth mentioned having a uncle and cousin and her last name is chase. At the end of the story, is said:Coming Fall 2015Magnus Chase and the Gods of Asgard,Book One,THE SWORD OF SUMMER(I'm really sad that this series is over, especially with the melodramatic, somewhat melancholy ending, my heart hurts but may be this next series will have more answers, may be Leo will return. I doubt it but I'm going to hope anyway.)