Sydneyfindsherselfface-to-facewithherlong-lostmother,IrinaDerevko,whoseintentionsforherdaughteraremadechillinglyclear.However,SydneymanagestoescapeandrejoinJackandWillintheirescapefromTaiwan.AfterarrivingbackinLosAngeles,SydneycontinueshersearchforVaughn,notknowingifheisdeadoraliveafterbeingsweptawaybyawallofwaterinTaipei.Will'slifeisforeverchangedwhenhelearnsthetruthaboutSD-6andSydney'slifeasadoubleagent.Also,DixonmustdecidewhetherornottoinformSloaneofSydney'ssuspiciousactivities.ButJackintervenesandcoversforSydneywholaterfindsVaughnwhohelpshertrytotrackdownhermotherIrinawho'ssearingforaRimbaldiartifactcalled'theBible.'