the screenplay never lets us forget that bourne was once an amoral assassin just like the ones who are pursuing him ... there is never really a true `` us '' versus `` them '' . 
(ROOT (S (S (NP (DT the) (NN screenplay)) (ADVP (RB never)) (VP (VBZ lets) (S (NP (PRP us)) (VP (VB forget) (SBAR (IN that) (S (NP (NNP bourne)) (VP (VBD was) (ADVP (RB once)) (NP (DT an) (JJ amoral) (NN assassin)) (PP (ADVP (RB just)) (IN like) (NP (NP (DT the) (NNS ones)) (SBAR (WHNP (WP who)) (S (VP (VBP are) (VP (VBG pursuing) (NP (PRP him))))))))))))))) (, ...) (S (NP (EX there)) (VP (VBZ is) (ADVP (RB never)) (ADVP (RB really)) (NP (NP (DT a) (JJ true) (`` ``) (PRP us) ('' '')) (PP (IN versus) (`` ``) (NP (PRP them)) ('' ''))))) (. .)))
(ROOT (S (S (NP (DT ) (NN )) (ADVP (RB )) (VP (VBZ ) (S (NP (PRP )) (VP (VB ) (SBAR (IN ) (S (NP (NNP )) (VP (VBD ) (ADVP (RB )) (NP (DT ) (JJ ) (NN )) (PP (ADVP (RB )) (IN ) (NP (NP (DT ) (NNS )) (SBAR (WHNP (WP )) (S (VP (VBP ) (VP (VBG ) (NP (PRP ))))))))))))))) (, ) (S (NP (EX )) (VP (VBZ ) (ADVP (RB )) (ADVP (RB )) (NP (NP (DT ) (JJ ) (`` ) (PRP ) ('' )) (PP (IN ) (`` ) (NP (PRP )) ('' ))))) (. )))