['they', 'detect', 'barrier', 'they', 'below']
['<PRP>', 'see-30.1', "Synset('hindrance.n.01')", '<PRP>', 'below']
However, they suddenly detect an energy barrier right below them.
However, <PRP> suddenly detect an Synset('animation.n.03') Synset('hindrance.n.01') right below <PRP>.