, ▁across ▁Super g irl ▁and ▁Ar row ▁( on ▁the ▁first ▁night ) ▁and ▁The ▁Flash ▁and ▁Leg ends ▁of ▁Tom orrow ▁( on ▁the ▁second ▁night ). ▁ ▁In ▁May ▁ 2 0 1 8 , ▁Ar row ▁star ▁Stephen ▁Am ell ▁announced ▁at ▁The ▁C W ▁up front s ▁that ▁the ▁next ▁Ar row verse ▁c ros so ver ▁would ▁feature ▁Bat w oman ▁and ▁Goth am ▁City . ▁The ▁c ros so ver , ▁titled ▁" Else world s ", ▁a ired ▁in ▁December ▁ 2 0 1 8 , ▁ahead ▁of ▁a ▁potential ▁ 2 0 1 9 ▁solo ▁series ▁for ▁the ▁character . ▁Super g irl ▁was ▁confirmed ▁to ▁have ▁a ▁particip ating ▁episode ▁in ▁August , ▁which ▁closed ▁out ▁the ▁three - part ▁c ros so ver , ▁trad ing ▁night s ▁with ▁The ▁Flash ▁just ▁for ▁the ▁event . ▁Therefore , ▁the ▁show ' s ▁particip ating ▁episode ▁a ired ▁on ▁T ues day , ▁December ▁ 1 1 . ▁The ▁end ▁of ▁" Else world s " ▁te ased ▁the ▁next ▁c ros so ver ▁event , ▁" C ris is ▁on ▁In finite ▁Earth s ". ▁Super g irl ' s ▁episode ▁opened ▁the ▁five - part ▁c ros so ver ▁on ▁December ▁ 8 , ▁ 2 0 1 9 , ▁with ▁the ▁final ▁two ▁install ments ▁air ing ▁on ▁January ▁ 1 4 , ▁ 2 0 2 0 . ▁At ▁the ▁end ▁of ▁the ▁event , ▁the ▁new ▁Earth -