Our next offering!" the ghoul shouted, his voice buzzing from the arrow in this throat. "Let us feed the Earth Mother!
-- Ghoul (Chapter 2 paragraph Page 11)

Importance: This is one of the ghouls who has bound Jason and the others. He demonstrates what the fountain of sand is capable of, showing Jason that whatever goes into the fountain is ground up into tiny bits and fed to Gaea.

At least the statue didn’t rumble, “DIE, UNBELIEVERS!” and zap the mortals to dust. Reyna had once dealt with a statue of the goddess Diana like that. It hadn’t been her most relaxing day.
-- Narrator (Chapter 7 paragraph Page 70)

Importance: This shows some characterization of Reyna, in that she is the leader and has had to deal with many unsavory acts in her praetorship.

THERE ARE TOO MANY OF THEM.” Reyna wondered bitterly how many times she’d said that in her demigod career.
-- Reyna (Chapter 8 paragraph Page 79)

Importance: This is when Gaea has overtaken Coach Hedge...