Nathan entered the cellar. Mason entered the cellar. The watermelon is in the green bathtub. Mason exited the cellar. Nathan moved the watermelon to the green suitcase. Mason entered the cellar.
Nathan think that Mason searches for the watermelon in the green suitcase.
 Nathan think that Mason searches for the watermelon in the green_bathtub
 Nathan think that Mason searches for the watermelon in the green_suitcase