, ▁and ▁production ▁wrapped ▁on ▁August ▁ 2 1 , ▁ 2 0 1 5 . ▁The ▁finale ▁was ▁fil med ▁with ▁the ▁option ▁to ▁be ▁broadcast ▁as ▁two ▁episodes ▁under ▁the ▁titles ▁" Im mort ality ▁Part ▁I " ▁and ▁" Im mort ality ▁Part ▁II ", ▁respectively . ▁The ▁production ▁codes ▁for ▁the ▁episodes ▁are ▁ 1 6 0 1 ▁and ▁ 1 6 0 2 . ▁ ▁Cast ing ▁ ▁During ▁the ▁CBS ▁ 2 0 1 5 ▁Up front , ▁Les ▁Moon ves ▁and ▁N ina ▁T ass ler ▁announced ▁that ▁former ▁lead ▁actors ▁Marg ▁Hel gen berger ▁and ▁William ▁Peters en ▁would ▁repr ise ▁their ▁roles ▁as ▁Catherine ▁Will ows ▁and ▁Gil ▁Gr iss om , ▁respectively . ▁Ted ▁Dans on , ▁who ▁star red ▁in ▁the ▁series ▁since ▁the ▁beginning ▁of ▁the ▁ 1 2 th ▁season , ▁also ▁returned ▁as ▁D . B . ▁Russell . ▁On ▁July ▁ 2 4 , ▁ 2 0 1 5 , ▁it ▁was ▁confirmed ▁that ▁both ▁George ▁E ads , ▁who ▁played ▁Nick ▁Sto kes ▁for ▁ 1 5 ▁seasons , ▁and ▁Elisabeth ▁Sh ue , ▁who ▁played ▁the ▁lead ▁role ▁of ▁Jul ie ▁Fin lay ▁for ▁four ▁seasons , ▁had ▁decl ined ▁options ▁to ▁return . ▁Elisabeth ▁Har no is , ▁J or ja ▁Fox , ▁Eric ▁Sz m anda , ▁Robert ▁David ▁Hall , ▁Wal lace ▁Lang ham , ▁David ▁B erman , ▁and ▁Jon ▁Well ner ▁all ▁repr ised ▁their ▁roles , ▁as ▁did ▁Paul ▁Gu