Percy is now in the deepest tunnels. He's got nothing left. He's turning mad. He has been betrayed. He is now another person.
'Thy six Half-Bloods shall walk on,
To thou with new form,
And shall seek true love,
Amongst guilt and lost.
But thy bravest shall not return,
Nor the others in live bod.
And thy hearts, shattered, dim,
Not to be missed.
But thine hero's soul,
Will stay together for all,
Though through great effort,
Past pain sore thy hero,
Thy light stand tall,
To accomplish thy own.'
Read The Prophecy of the Lost first.