the story alone could force you to scratch a hole in your head . 
(ROOT (S (NP (NP (DT the) (NN story)) (ADVP (RB alone))) (VP (MD could) (VP (VB force) (NP (PRP you)) (S (VP (TO to) (VP (VB scratch) (NP (DT a) (NN hole)) (PP (IN in) (NP (PRP$ your) (NN head)))))))) (. .)))
(ROOT (S (NP (NP (DT ) (NN )) (ADVP (RB ))) (VP (MD ) (VP (VB ) (NP (PRP )) (S (VP (TO ) (VP (VB ) (NP (DT ) (NN )) (PP (IN ) (NP (PRP$ ) (NN )))))))) (. )))