The Crown Of Ptolemy Percy Jackson & The Kane Chronicles Crossover Series, Book 3.

In their first encounter, demigod Percy Jackson and magician Carter Kane had to battle a giant crocodile on Long Island. A month later, Annabeth Chase ran into Carter's sister, Sadie, on the A train to Rockaway, where the pair fought a god named Serapis. Now trouble is brewing again, this time on Governor's Island. An ancient Egyptian magician named Setne has come back from the dead and is experimenting with Egyptian and Greek magic, trying to be...