User blog comment:Darkcloud1111/Official "The Sea of Monsters (movie)" Discussion/@comment-7742465-20130703043838/@comment-3146930-20130703232003

It actually would be a lot easier then you think. Most of the characters from The Titan's Curse are either characters we know (Grover, Percy, Annabeth, ect), or characters that die (Zoe and Bianca). Same could be said for The Battle of the Labyrinth, as the only new character we get is Rachel. Now in my mind, they could actually cut out the two books and make the final movie by:
 * Replace Nico's idea for Percy to bath in the River Styx by having someone else suggest it. Maybe a god or have someone like Clarisse mention the Styx in passing. Maybe Percy comes up with the idea himself. It would completely remove Nico from the story, but Nico is more of a background character, important because he moves the plot. Maybe have Annabeth take him to May's house as she has been there before, so has Thalia.
 * Have Kronos rise at the end of The Sea of Monsters, but have the demigods defeat him, forcing him to join with Luke to survive.
 * The Hunters of Artemis could arrive at the start of the battle and Thalia could join them to better protect Olympus (and not turn 16)
 * Have Thalia biologically a day or two older then Percy, then the above thing would work better.
 * Not include Rachel Elizabeth Dare. Her main role is to act as a love rival for Annabeth and become the new Oracle. If you removed her, all that would happen would be no new Oracle; which isn't important.

This is just a few ways they can get the third movie out, if they were to skip Books 3 and 4