▁printer , ▁which ▁not ▁only ▁a ids ▁Mer ed ith ' s ▁research , ▁but ▁also ▁helps ▁Crist ina ▁and ▁Sh ane ▁with ▁their ▁condu its . ▁D erek ▁and ▁Dr . ▁Call ie ▁Tor res ▁( S ara ▁Ram ire z ) ▁teams ▁up ▁with ▁the ▁White ▁House ▁to ▁work ▁on ▁a ▁brain ▁mapping ▁project , ▁a ▁project ▁that ▁will ▁identify ▁which ▁parts ▁of ▁the ▁brain ▁are ▁responsible ▁for ▁different ▁functions . ▁Dr . ▁Mir anda ▁Ba iley ▁( Ch andra ▁Wilson ) ▁is ▁also ▁at ▁the ▁hel m ▁of ▁a ▁project ▁mapping ▁out ▁the ▁human ▁gen ome , ▁a ▁project ▁that ▁helps ▁her ▁save ▁her ▁b ubble - boy ▁patient , ▁Br aden . ▁Alex ▁accepts ▁a ▁job ▁offer ▁from ▁Dr . ▁Oliver ▁Leb ack es , ▁a . k . a . ▁Dr . ▁" But th ole ," ▁to ▁work ▁at ▁his ▁private ▁practice . ▁ ▁While ▁separated , ▁Dr . ▁Arizona ▁Rob b ins ▁( J ess ica ▁Cap sh aw ) ▁continues ▁to ▁sleep ▁around , ▁this ▁time ▁with ▁Dr . ▁Le ah ▁Mur phy ▁( T essa ▁Fer rer ). ▁After ▁some ▁he ated ▁f ights , ▁Call ie ▁and ▁Arizona ▁recon cile ▁their ▁differences ▁and ▁move ▁back ▁in ▁together . ▁They ▁eventually ▁decide ▁that ▁they ▁would ▁like ▁to ▁have ▁another ▁baby , ▁and ▁Arizona ▁tells ▁Call ie ▁that ▁she ▁would ▁like ▁for ▁her ▁to ▁carry ▁it . ▁Crist ina ▁and ▁Dr . ▁O wen ▁H unt ▁( Ke vin ▁McK idd ) ▁gradually ▁take ▁their