I haven't tried opium, but cannot imagine that Opium smells much like an opium den; and it is impossible to guess at what the millennium will smell like.
( ( ( ( ( I ( ( ( ( ( have n't ) ( tried opium ) ) , ) but ) ( ( can not ) ( imagine ( that ( Opium ( ( smells much ) ( like ( an ( opium den ) ) ) ) ) ) ) ) ) ) ; ) and ) ( it ( is ( impossible ( to ( guess ( at ( what ( ( the ( millennium ( will smell ) ) ) like ) ) ) ) ) ) ) ) ) . )
(ROOT (S (S (NP (PRP I)) (VP (VP (VBP have) (RB n't) (VP (VBN tried) (NP (NN opium)))) (, ,) (CC but) (VP (MD can) (RB not) (VP (VB imagine) (SBAR (IN that) (S (NP (NNP Opium)) (VP (VBZ smells) (NP (RB much)) (PP (IN like) (NP (DT an) (NN opium) (NN den)))))))))) (: ;) (CC and) (S (NP (PRP it)) (VP (VBZ is) (ADJP (JJ impossible) (S (VP (TO to) (VP (VB guess) (PP (IN at) (SBAR (WHNP (WP what)) (S (NP (DT the) (JJ millennium) (NN will) (NN smell)) (VP (VBP like))))))))))) (. .)))
I don't believe that Opium perfume smells like an opium den. 
( I ( ( ( do n't ) ( believe ( that ( ( Opium perfume ) ( smells ( like ( an ( opium den ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP I)) (VP (VBP do) (RB n't) (VP (VB believe) (SBAR (IN that) (S (NP (NNP Opium) (NN perfume)) (VP (VBZ smells) (PP (IN like) (NP (DT an) (NN opium) (NN den)))))))) (. .)))