The third book in the bestselling Percy Jackson and the Olympians series. Now with a new cover look! Discover the story behind the Disney+ series. HALF BOY - HALF GOD - ALL HERO. It's not every day you find yourself in combat with a half-lion, half human. . . Percy Jackson has a lot on his plate. A powerful goddess has gone missing. The Greek gods are on the brink of war with the Titans. And there's the minor threat of a mystery beast that could destroy Mount Olympus forever. This time, Percy's going to need help and he's found two powerful demigods for the job. . .There's just the small problem of the prophecy. The one that has predicted not all of them will survive. But when you're the son of a Greek god, it happens. Right?