ena ▁Par then os ▁will ▁restore ▁Mount ▁Olymp us , ▁A rach ne ▁goes ▁into ▁a ▁fit ▁and ▁brings ▁down ▁her ▁chamber ▁enough ▁to ▁open ▁a ▁ch asm ▁to ▁T art arus . ▁As ▁A rach ne ▁falls ▁down ▁into ▁T art arus , ▁she ▁man ages ▁to ▁ens n are ▁An nab eth ▁at ▁the ▁last ▁minute ▁as ▁she ▁and ▁Per cy ▁go ▁down ▁the ▁ch asm ▁with ▁N ico ▁prom ising ▁to ▁meet ▁them ▁at ▁the ▁Do ors ▁of ▁Death . ▁In ▁The ▁House ▁of ▁H ades , ▁A rach ne ▁amb ush es ▁Per cy ▁and ▁An nab eth ▁which ▁ended ▁with ▁Per cy ▁using ▁R ipt ide ▁to ▁defeat ▁A rach ne . ▁ ▁An ta eus ▁– ▁A ▁half - gi ant ▁who ▁is ▁the ▁son ▁of ▁P ose id on ▁and ▁G ae a . ▁He ▁was ▁inv inci ble ▁as ▁long ▁as ▁he ▁maintained ▁contact ▁with ▁the ▁ground , ▁so ▁Per cy ▁defeated ▁him ▁by ▁h anging ▁him ▁in ▁the ▁air ▁with ▁ch ains . ▁ ▁Arg us ▁– ▁A ▁hum ano id ▁figure ▁with ▁eyes ▁all ▁over ▁his ▁body ▁who ▁works ▁as ▁a ▁security ▁guard ▁at ▁Camp ▁Half - B lo od . ▁He ▁rarely ▁speak s ▁as ▁he ▁is ▁said ▁to ▁have ▁an ▁eye ▁on ▁his ▁tongue . ▁He ▁car es ▁for ▁H era ▁a ▁lot ▁because ▁she ▁is ▁his ▁cre ator . ▁ ▁B lem my ae ▁- ▁A ▁race ▁of ▁head less ▁people ▁with ▁their ▁fa cial ▁features ▁on ▁their ▁ch est