this might have been an eerie thriller 
(ROOT (S (NP (DT this)) (VP (MD might) (VP (VB have) (VP (VBN been) (NP (DT an) (JJ eerie) (NN thriller)))))))
(ROOT (S (NP (DT )) (VP (MD ) (VP (VB ) (VP (VBN ) (NP (DT ) (JJ ) (NN )))))))