toward the light -- the light of the exit sign 
(ROOT (PP (IN toward) (NP (NP (DT the) (NN light)) (, --) (NP (NP (DT the) (NN light)) (PP (IN of) (NP (DT the) (NN exit) (NN sign)))))))
(ROOT (PP (IN ) (NP (NP (DT ) (NN )) (, ) (NP (NP (DT ) (NN )) (PP (IN ) (NP (DT ) (NN ) (NN )))))))