The demigod files is a book about Percy Jackson and three of his most dangerous stories.
Story 1: Percy is in school in New York when he sees Clarisse out the window of his classroom, he asks to go to the bathroom but instead he goes to ask Clarisse what she is doing there. She says that she borrowed her dad's chariot for a drive and her dad told her to return it by the evening, but her mean brothers, Phobos and Deimos stole it as a prank, and Phobos appears there and makes fun of them, but then Percy finds out that Phobos is the god of fear, so that means that he can show anybody their fear, and he shows Clarisse her fear. Percy attacks him and he disappears giving them a clue that the chariot is in a zoo an an island nearby. By that Percy knows that there is a zoo on Staten Island, they are taking a quick ferry but they find Deimos and fight him a little. They reach the island zoo and they find the chariot, but something is fishy, then both of the brothers appear, and they fight, at the end they defeat them and return the chariot to her dad.
Story 2: Percy is at Camp-Half-Blood playing capture the flag, him and his friend from his team are trying to find the other team's flag but they find Mymerkes, which means ancient ants in Greek, Mymerkes are about the size about a golden retriever, and they see the ants carrying a metallic dragon head, but Percy's friend run's to battle the ants and gets captured by them. And then they find help by Annabeth and her friend. They suddenly realize that the dragon head is the missing head of the golden dragon, the dragon that used to protect camp, which went missing a long time ago. The steal the head from the ants and look for the body, they find it and they assemble the head back on and commands the dragon to bring Percy's friend back and he does, and the dragon defeats the Mymerkes too. The end.
Story 3: Percy, Thalia, and Nico are sent on a quest, to get back Hades' stolen sword. They are given a flower that will help them find it, they go to find it and they are stopped by this river that if you go in it you forget everything, so Percy controls the water in the river so they can cross it, they cross it and they find the thief, a demigod named Ethan Nakamura, he gives it to a Titan, who Percy defeat's and at the end he returns the sword to Hades.
My favorite story was the 3rd one.