▁her , ▁May a ▁and ▁Eli . ▁He ▁met ▁Em ily ▁Pr ent iss , ▁then ▁the ▁chief ▁of ▁Inter pol ' s ▁London ▁office , ▁during ▁his ▁line ▁of ▁work . ▁He ▁was ▁also ▁ment ored ▁by ▁David ▁Ros si ▁( J oe ▁M ante g na ). ▁Stephen ' s ▁first ▁case ▁concerned ▁a ▁terror ist ▁cell ▁in ▁Belg ium , ▁and ▁three ▁agents ▁were ▁sent ▁under cover ▁to ▁in fil tr ate ▁it . ▁However , ▁Stephen ' s ▁profile ▁was ▁wrong , ▁and ▁this ▁resulted ▁in ▁the ▁death s ▁of ▁the ▁under cover ▁agents . ▁He ▁eventually ▁moved ▁on ▁from ▁the ▁tra uma ▁and ▁improved ▁as ▁he ▁went ▁along ▁in ▁his ▁career . ▁He ▁and ▁other ▁B AP ▁agents , ▁including ▁his ▁long time ▁friend ▁Sam ▁B ower , ▁were ▁sent ▁under cover ▁to ▁investigate ▁cor ruption ▁in ▁the ▁Russian ▁government . ▁Walker ' s ▁skills ▁include ▁being ▁fl uent ▁in ▁Russian ▁and ▁playing ▁the ▁trom bone . ▁In ▁the ▁season ▁ 1 3 ▁premi ere , ▁it ▁is ▁revealed ▁he ▁had ▁died ▁in ▁the ▁car ▁crash ▁Mr . ▁Sc r atch ▁had ▁arranged ▁as ▁a ▁trap ▁for ▁the ▁team ▁at ▁the ▁end ▁of ▁season ▁ 1 2 . ▁ ▁Matt ▁Sim m ons ▁( Daniel ▁Hen ney ) ▁( se asons ▁ 1 3 – 1 5 ; ▁guest ▁seasons ▁ 1 0 , ▁ 1 2 ) ▁ ▁super vis ory ▁special ▁agent , ▁and ▁former ▁member ▁of ▁the ▁International ▁Response ▁Team . ▁ ▁Sim m ons