Rick Riordan said this quote

I held out the rune for Hearthstone. ‘I know what it feels like to be an empty cup, to have everything taken away from you. But you’re not alone. However much magic you need to use, it’s okay. We’ve got you. We’re your family.’Hearth’s eyes rimmed with green water. He signed to us, and this time I think he actually meant I love you and not the giantesses are drunk.He took the rune and set it between the prongs of his new staff. The stone snapped into place the same way my pendant did on its chain. The symbol perthro glowed with a gentle gold light.My sign, he announced. My family’s sign.Blitzen sniffled. ‘I like that. A family of four empty cups!’Sam wiped her eyes. ‘Suddenly I feel thirsty.’‘Al-Abbas,’ I said, ‘I nominate you for the role of annoying sister.’‘Shut up, Magnus.