it begins to drag two-thirds through , when the melodramatic aspects start to overtake the comedy 
(ROOT (S (NP (PRP it)) (VP (VBZ begins) (S (VP (TO to) (VP (VB drag) (ADVP (NP (CD two) (HYPH -) (NNS thirds)) (RB through)) (, ,) (SBAR (WHADVP (WRB when)) (S (NP (DT the) (JJ melodramatic) (NNS aspects)) (VP (VBP start) (S (VP (TO to) (VP (VB overtake) (NP (DT the) (NN comedy))))))))))))))
(ROOT (S (NP (PRP )) (VP (VBZ ) (S (VP (TO ) (VP (VB ) (ADVP (NP (CD ) (HYPH ) (NNS )) (RB )) (, ) (SBAR (WHADVP (WRB )) (S (NP (DT ) (JJ ) (NNS )) (VP (VBP ) (S (VP (TO ) (VP (VB ) (NP (DT ) (NN ))))))))))))))