▁defeated ▁a ▁Roman ▁leader ▁who ▁fought ▁with ▁Ga ia , ▁Oct av ian ) ▁An ▁o ath ▁to ▁keep ▁with ▁a ▁final ▁breath , ▁( Le o ' s ▁o ath ▁to ▁come ▁back ▁to ▁a ▁mag ical ▁island ▁where ▁his ▁love ▁waited ) ▁And ▁fo es ▁bear ▁arms ▁to ▁the ▁Do ors ▁of ▁Death . ▁( The ▁aw ak ened ▁gi ants ▁and ▁T art arus ▁guard ▁the ▁doors ▁of ▁death ) ▁Seven ▁dem ig ods An nab eth ▁Ch ase , ▁Leo ▁Val de z , ▁Per cy ▁Jackson ▁and ▁Pi per ▁Mc Le an ▁from ▁Camp ▁Half - B lo od , ▁with ▁Jason ▁Grace , ▁Frank ▁Z hang , ▁and ▁Haz el ▁Le ves que ▁from ▁Camp ▁Jup iter join ▁forces . ▁A ▁storm ▁or ▁a ▁fire ▁will ▁destroy ▁the ▁world ▁( Wh ich ▁means ▁either ▁Leo ▁or ▁Jason ▁will ▁have ▁a ▁terrible ▁fate ▁in ▁store ). ▁The ▁last ▁line ▁details ▁how ▁ 2 ▁dem ig ods , ▁a ▁giant , ▁and ▁a ▁tit an ▁will ▁free ▁the ▁Do ors ▁of ▁Death . ▁ ▁Some ▁other ▁important ▁characters ▁are ▁N ico ▁di ▁Ang elo , ▁Son ▁of ▁H ades , ▁Re yna ▁Av ila ▁Ram ire z - A rell ano , ▁Pra et or ▁of ▁Camp ▁Jup iter ▁and ▁daughter ▁of ▁Bell ona , ▁and ▁G le es on ▁H edge , ▁a ▁sat yr . ▁In ▁the ▁books , ▁they ▁are ▁the ▁main ▁people ▁trying ▁to ▁bring ▁peace ▁between ▁the ▁Gree ks ▁and ▁the ▁Rom ans ▁while