Continuity mistake: On page 305 of the first edition published 2012, Piper and Annabeth sent a dream vision to Camp Half-Blood, but on page 306 they refer to it as an Iris-message.
7 mistakes in Beetlejuice you never spotted
10 biggest mistakes of 2017
A new menu and more - thoughts welcome...
25 biggest mistakes in classic Disney movies
First pictures of Josh Brolin as Cable for Deadpool 2