Complex sentence: Annabeth kisses Percy in "The Battle of the Labyrinth" when she thinks he is going to die instead of punching him as he suspects and they begin to date in "The Last Olympian".
Split into simpler sentences: Annabeth kisses Percy in "The Battle of the Labyrinth" when she thinks he is going to die instead of punching him as he suspects. They begin to date in "The Last Olympian".