(S (S (BASENP (NNS Researchers)) (VP (ADVP (RB therefore)) (VP (VBP conclude) (SBAR (IN that) (S (BASENP (DT the) (NNP Archer)) (VP (VP (VBD came) (PP (TO to) (BASENP (NNP Stonehenge)))) (S (VP (TO to) (VP (VB be) (VP (VBN healed))))))))))) (PERIOD .))