You've got the keys still, haven't you, Poirot? I asked, as we reached the door of the locked room. 
( ( You ( 've ( ( got ( the keys ) ) still ) ) ) ( , ( ( ( ( have n't ) ( ( you , ) ( ( Poirot ? ) ( I ( ( asked , ) ( as ( we reached ) ) ) ) ) ) ) ( ( the door ) ( of ( the ( locked room ) ) ) ) ) . ) ) )
(ROOT (S (S (NP (PRP You)) (VP (VBP 've) (VP (VBN got) (NP (DT the) (NNS keys)) (ADVP (RB still))))) (, ,) (VP (VBP have) (RB n't) (NP (NP (PRP you)) (, ,) (NP (NP (NNP Poirot) (. ?)) (SBAR (S (NP (PRP I)) (VP (VBD asked) (, ,) (SBAR (IN as) (S (NP (PRP we)) (VP (VBD reached)))))))))) (NP (NP (DT the) (NN door)) (PP (IN of) (NP (DT the) (JJ locked) (NN room)))) (. .)))
Poirot had left the keys in the car.
( Poirot ( ( had ( ( left ( the keys ) ) ( in ( the car ) ) ) ) . ) )
(ROOT (S (NP (NNP Poirot)) (VP (VBD had) (VP (VBN left) (NP (DT the) (NNS keys)) (PP (IN in) (NP (DT the) (NN car))))) (. .)))