the irrelevant as on the engaging , which gradually turns what time 
(ROOT (FRAG (NP (DT the) (JJ irrelevant)) (PP (IN as) (PP (IN on) (NP (NP (DT the) (NN engaging)) (, ,) (SBAR (WHNP (WDT which)) (S (ADVP (RB gradually)) (VP (VBZ turns) (FRAG (WHNP (WDT what) (NN time)))))))))))
(ROOT (FRAG (NP (DT ) (JJ )) (PP (IN ) (PP (IN ) (NP (NP (DT ) (NN )) (, ) (SBAR (WHNP (WDT )) (S (ADVP (RB )) (VP (VBZ ) (FRAG (WHNP (WDT ) (NN )))))))))))