What happened after percy smashed the three pearls in chapter 19

In chapter 19 Percy remembers the three pearls in his pocket from the Nereid, but Hades says that each will save only one person, so either one of them or his mother must be left behind. Grover and Annabeth both offer to stay behind, and Percy wants desperately to sacrifice himself for his mother, but he knows she would never allow it and remembers the words of the prophecy: "You will fail to save what matters most in the end." Percy promises Hades he will find his helm and then each of the three of them smashes a pearl at their feet, then are taken back to the surface in milky white bubbles. They make it back up and realize Hades has sent an earthquake to shake Los Angeles, and it is the morning of the summer solstice. Percy has only two thoughts in mind: making it to Olympus to return Zeus's bolt, and having a conversation with the god who tricked him.