Percy Jackson and the Olympians Season 2 has taken some big leaps when it comes to changes in the show compared to the source material, Rick Riordan's novels.The TV adaptation of Riordan's novels, with Riordan himself involved as a co-creator and an executive producer, has been sufficiently aligned with the novels so far; however, there have been some changes to the story, especially to the narratives that the fifth episode of the second season tackles.Directed by Catriona McKenzie and written by Sarah Watson, the fifth episode tackles Circe's island plotline as well as Polyphemus, but there have been some big changes to C.C. or Circe's character, played by Rosemarie DeWitt.Keep reading to find out what these major book changes were to Percy Jackson and the Olympians, Season 2, Episode 5.Percy Jackson and the Olympians Season 2 makes some major book changesPercy Jackson and the Olympians Season 2 (Image via Disney)Percy Jackson and the Olympians Season 2 Episode 5 has a wide range of ideas and plotlines that it tries to fit into the episode, and that results in some major book changes. One of these changes is how Circe's islands and the sirens' narrative have been brought to life in the latest episode.The fifth episode finds the narrative splitting into two yet again. Grover, who has been apart from the whole gang for so long, is seen once again, and Clarisse's ship explosion finds her waking up near the Golden Fleece. On the other side, Annabeth and Percy are at Circe's Island, a major plotline from The Sea of Monsters, which has been adapted slightly differently for the show.In Rick Riordan's book The Sea of Monsters, after Clarisse's ship explosion, Percy and Annabeth are at C.C.'s spa and resort, which they escape to, then end up at the Sirens' island and finally Polyphemus' lair. Percy Jackson and the Olympians Season 2 Episode 5 makes a big book change by tying C.C.'s home and the Sirens' Island narratives together.In the show, C.C., aka Circe, reveals herself to be a sorceress who uses her spa resort as a means of helping heroes discover their one fatal flaw. But this is used by the Sirens to ensure that the heroes do not escape the island and are lured with the Sirens' song, the creatures that are to stop anybody from entering or leaving the island.The mixing of these two narratives has made Circe a much more layered and grey character instead of a straight-up villain, because even though her goal is to help the heroes and stems from a need to be connected, her methods and her choices are not all helpful.Nevertheless, Circe never comes off as venomous or evil in any way, and her character is well-written and well-acted, even if it's a big change from the book. Percy Jackson and the Olympians Season 2 Episode 5 changes from the book have made the show better, much like the changes made to Medusa's character in Season 1.Keep reading Soap Central for more such interesting insights into your favorite shows!