▁known ▁as ▁the ▁H eg em ony . ▁Though ▁the ▁H eg em ony ▁has ▁large - scale ▁inter stell ar ▁travel ▁and ▁high ▁technology , ▁it ▁has ▁not ▁yet ▁returned ▁to ▁the ▁Empire ' s ▁level ▁of ▁techn ological ▁pro w ess . ▁ ▁T iam at ▁is ▁an ▁ocean ic ▁planet , ▁accessible ▁to ▁the ▁H eg em ony ▁only ▁through ▁w orm hole ▁travel . ▁The ▁gravit ational ▁pull ▁of ▁T iam at ' s ▁tw in ▁sun s ▁influence ▁the ▁" Black ▁Gate ". ▁It ▁only ▁remains ▁open ▁for ▁cycles ▁of ▁ 1 5 0 ▁years ; ▁when ▁it ▁is ▁closed , ▁no ▁off world ▁travel ers ▁are ▁able ▁to ▁reach ▁T iam at ▁for ▁more ▁than ▁a ▁century . ▁The ▁residents ▁of ▁T iam at ▁are ▁split ▁into ▁two ▁cl ans : ▁" W inter s ", ▁who ▁advoc ate ▁techn ological ▁progress ▁and ▁trade ▁with ▁off world ers , ▁and ▁" Sum mers ", ▁who ▁depend ▁on ▁their ▁folk ▁trad itions ▁and ▁rig id ▁social ▁dist in ctions ▁for ▁surv ival . ▁Every ▁ 1 5 0 ▁years , ▁control ▁of ▁T iam at ' s ▁government ▁switch es ▁between ▁Winter ▁rule ▁and ▁Summer ▁rule . ▁Inter stell ar ▁travel ▁between ▁T iam at ▁and ▁the ▁H eg em ony ▁is ▁only ▁possible ▁during ▁the ▁ 1 5 0 ▁years ▁of ▁Winter ▁rule , ▁and ▁a ▁single ▁woman ▁rules ▁the ▁entire ▁planet : ▁a ▁" S now ▁Queen " ▁in ▁Winter , ▁a ▁" Sum mer ▁Queen