to head off in its own direction 
(ROOT (S (VP (TO to) (VP (VB head) (ADVP (RP off)) (PP (IN in) (NP (PRP$ its) (JJ own) (NN direction)))))))
(ROOT (S (VP (TO ) (VP (VB ) (ADVP (RP )) (PP (IN ) (NP (PRP$ ) (JJ ) (NN )))))))