buried at the heart of his story 
(ROOT (VP (VBN buried) (PP (IN at) (NP (NP (DT the) (NN heart)) (PP (IN of) (NP (PRP$ his) (NN story)))))))
(ROOT (VP (VBN ) (PP (IN ) (NP (NP (DT ) (NN )) (PP (IN ) (NP (PRP$ ) (NN )))))))