an inexplicable nightmare , right down to the population 
(ROOT (NP (NP (DT an) (JJ inexplicable) (NN nightmare)) (, ,) (ADVP (RB right) (RB down) (PP (IN to) (NP (DT the) (NN population))))))
(ROOT (NP (NP (DT ) (JJ ) (NN )) (, ) (ADVP (RB ) (RB ) (PP (IN ) (NP (DT ) (NN ))))))