▁he , ▁Frank ▁Z hang , ▁and ▁Haz el ▁Le ves que ▁travel ▁to ▁Al aska ▁to ▁stop ▁the ▁rise ▁of ▁the ▁giant ▁Al cy one us ▁and ▁free ▁the ▁god ▁Th an atos , ▁whom ▁the ▁giant ▁has ▁captured . ▁After ▁successfully ▁comple ting ▁their ▁mission , ▁the ▁group ▁returns ▁to ▁Camp ▁Jup iter ▁to ▁defend ▁it ▁from ▁yet ▁another ▁giant , ▁Poly b otes , ▁and ▁his ▁army . ▁After ▁rep elling ▁this ▁invasion , ▁the ▁dem ig ods ▁from ▁Camp ▁Jup iter ▁go ▁to ▁meet ▁the ▁deleg ation ▁from ▁Camp ▁Half - B lo od ▁arriv ing ▁in ▁the ▁flying ▁ship ▁known ▁as ▁the ▁Ar go ▁II . ▁ ▁The ▁Mark ▁of ▁Ath ena ▁ ▁After ▁the ▁Ar go ▁II ▁un int ention ally ▁fires ▁on ▁Camp ▁Jup iter , ▁the ▁seven ▁dem ig ods ▁of ▁the ▁" Prop he cy ▁of ▁Seven " ▁- ▁Per cy ▁Jackson , ▁An nab eth ▁Ch ase , ▁Haz el ▁Le ves que , ▁Frank ▁Z hang , ▁Jason ▁Grace , ▁Pi per ▁Mc Le an , ▁and ▁Leo ▁Val de z ▁- ▁r ush ▁to ▁escape ▁the ▁anger ed ▁Roman ▁camp ers . ▁They ▁travel ▁to ▁Rome ▁following ▁the ▁Mark ▁of ▁Ath ena , ▁a ▁mag ical ▁t alis man ▁designed ▁to ▁lead ▁children ▁of ▁Ath ena ▁( like ▁An nab eth ) ▁to ▁the ▁missing ▁Ath ena ▁Par then os . ▁During ▁their ▁journey , ▁they ▁hear ▁that ▁N ico ▁di ▁Ang elo ▁has ▁been ▁captured ▁by ▁the ▁Alo ada e