Percy would like to be able to say that he had some kind of deep revelation on his way down to the Mississippi River, that he was able to come to terms with his mortality. But in actual fact, his only thought was
And no wonder. The river's hurtling towards Percy at the speed of a truck. The wind has ripped the very breath from his lungs and all the objects of the landscape—steeples, skyscrapers, and bridges—tumble in and out of his vision with truly astonishing rapidity.
All of a sudden, Percy hits the water. Although, he's surprised to discover that it doesn't actually hurt. The next thing he knows, he's reached the bottom of the murky, muddy, Mississippi River. It's pretty revolting down there, what with all the old shoes and discarded plastic bags. But Percy's feeling fine, not least because he can no longer feel the Chimera poison coursing through his veins.
Even more remarkably, Percy doesn't feel wet. He's right at the bottom of the Mississippi River, and yet he feels perfectly dry. Things get even weirder when Percy picks up a discarded cigarette lighter and actually manages to get a tiny flame from it.
But most remarkably of all, Percy discovers, much to his astonishment, that he can breathe underwater. And there's nothing labored about his breathing, either; he can actually breathe normally.