* The Heroes of Olympus series: While not directly in the Percy Jackson series, *The Heroes of Olympus* is a sequel series that features Percy and the other main characters from the original series. It expands on the world and mythology presented in the original books.
* The Trials of Apollo series: This series follows Apollo as he's stripped of his godly powers and forced to walk the earth as a mortal teenager. It connects to the Percy Jackson world through its shared mythology and characters.
* The Kane Chronicles series: This series, while not directly related to Percy Jackson, also features Egyptian mythology and introduces new heroes.
* The Magnus Chase series: Similar to *The Kane Chronicles*, this series focuses on Norse mythology and a new group of heroes.
* Rick Riordan's creative process: Rick Riordan has mentioned in interviews that he's open to returning to the Percy Jackson universe, but only if the story feels right.
In conclusion, while there are no confirmed plans for new Percy Jackson novels, there are a number of interconnected series that continue the world-building and introduce new adventures within the Rick Riordan universe. It's always possible that he might revisit Percy Jackson, but for now, we can enjoy the existing series and wait to see what he writes next!