Tommy realized perfectly that in his own wits lay the only chance of escape, and behind his casual manner he was racking his brains furiously.
( ( ( ( ( Tommy ( ( realized perfectly ) ( that ( ( in ( his ( own wits ) ) ) ( lay ( ( the ( only chance ) ) ( of escape ) ) ) ) ) ) ) , ) and ) ( ( behind ( his ( casual manner ) ) ) ( he ( was ( ( racking ( his brains ) ) furiously ) ) ) ) ) . )
(ROOT (S (S (NP (NNP Tommy)) (VP (VBD realized) (ADVP (RB perfectly)) (SBAR (IN that) (S (PP (IN in) (NP (PRP$ his) (JJ own) (NNS wits))) (VP (VBD lay) (NP (NP (DT the) (JJ only) (NN chance)) (PP (IN of) (NP (NN escape))))))))) (, ,) (CC and) (S (PP (IN behind) (NP (PRP$ his) (JJ casual) (NN manner))) (NP (PRP he)) (VP (VBD was) (VP (VBG racking) (NP (PRP$ his) (NNS brains)) (ADVP (RB furiously))))) (. .)))
Tommy was keeping a calm demeanor, though his mind was racing with thoughts of escaping.
( Tommy ( ( was ( ( ( keeping ( a ( calm demeanor ) ) ) , ) ( though ( ( his mind ) ( was ( racing ( with ( thoughts ( of escaping ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Tommy)) (VP (VBD was) (VP (VBG keeping) (NP (DT a) (NN calm) (NN demeanor)) (, ,) (SBAR (IN though) (S (NP (PRP$ his) (NN mind)) (VP (VBD was) (VP (VBG racing) (PP (IN with) (NP (NP (NNS thoughts)) (PP (IN of) (S (VP (VBG escaping)))))))))))) (. .)))