['alien', 'strip', 'they', 'underwear', 'to']
["Synset('person.n.01')", 'dress-41.1.1', '<PRP>', "Synset('garment.n.01')", 'to']
The aliens have stripped them down to their underwear.
the Synset('person.n.01') have stripped <PRP> down to <PRP> Synset('garment.n.01').