Castle star Nathan Fillion has joined the cast of Percy Jackson: Sea of Monsters for 20th Century Fox and director Thor Freudenthal.

The actor will portray Hermes, who was the messenger to the Gods in Greek mythology. In this franchise, which is adapted from the young adult novels by Rick Riordan, Hermes is also the father to the antagonist Luke (Jake Abel). Dylan Neal portrayed Hermes in Percy Jackson & the Olympians: Lightning Thief. Logan Lerman, Alexandra Daddario, and Brandon T. Jackson are returning for the sequel.

Thor Freudenthal is directing Percy Jackson: Sea of Monsters, from an adapted script by Scott Alexander and Larry Karaszewski. Percy Jackson & the Olympians: Lightning Thief director Chris Columbus is producing the sequel alongside Karen Rosenfelt.

It isn't known when production will begin on Percy Jackson: Sea of Monsters.