They now heard a trips Within a something .
(ROOT_0 (S_0 (ATS_3 (ATS_1 (NP_1 (PRP_0 They)) (ADVP_0 (RB_0 now))) (VP_3 (VBD_0 heard) (NP_3 (NP_6 (DT_0 a) (NNS_1 trips)) (PP_0 (IN_1 Within) (NP_5 (DT_0 a) (NN_2 something)))))) (DOT_0 .)))