I'll be flying in on the 'fourth'. [=the fourth day of the month]
He got a base hit in the 'fourth'. [=the fourth inning]
She drank a 'fourth' of the bottle.
(..) We have you on a little leash, professor. Why would I try to run? I didn't do anything. So, what do you think about the fourth line of text... ...Fache wiped clean before you arrived? He brought you here to force a confession, Professor Langdon. He's still in there? (..)2006 The Da Vinci Code