unfolds with such a wallop of you-are-there immediacy that when the bullets start to fly , your first instinct is to duck . 
(ROOT (S (VP (VBZ unfolds) (PP (IN with) (NP (NP (NP (PDT such) (DT a) (NN wallop)) (PP (IN of) (NP (NML (S (NP (PRP you)) (, -) (VP (VBP are) (, -) (ADVP (PRP$ there))))) (NN immediacy)))) (SBAR (IN that) (S (SBAR (WHADVP (WRB when)) (S (NP (DT the) (NNS bullets)) (VP (VBP start) (S (VP (TO to) (VP (VB fly))))))) (, ,) (NP (PRP$ your) (JJ first) (NN instinct)) (VP (VBZ is) (S (VP (TO to) (VP (VB duck)))))))))) (. .)))
(ROOT (S (VP (VBZ ) (PP (IN ) (NP (NP (NP (PDT ) (DT ) (NN )) (PP (IN ) (NP (NML (S (NP (PRP )) (, ) (VP (VBP ) (, ) (ADVP (PRP$ ))))) (NN )))) (SBAR (IN ) (S (SBAR (WHADVP (WRB )) (S (NP (DT ) (NNS )) (VP (VBP ) (S (VP (TO ) (VP (VB ))))))) (, ) (NP (PRP$ ) (JJ ) (NN )) (VP (VBZ ) (S (VP (TO ) (VP (VB )))))))))) (. )))