Sentence:  It dawns on you that instead of a lump to fill the <WSD>seat</WSD> across the bridge table from you , he was a man , and that because Gratt Shafer was making you miserable , you were passing it down to him , to Gratt Shafer 's substitute , that other guy . 
Meaning of the word marked with <WSD> tags:  a space reserved for sitting (as in a theater or on a train or airplane)