This is a con-crew role. He is playing a wealthy, gullible fool. The Con Man finds someone avaricious (the mark) to "help him take down" the Napier. The mark sees the big, juicy target, and bankrolls the play. Conman and Napier fade away with the bankroll. The word 'napier' may have something to do with Lord Napier. In any case it means "fool". Not related to any guy named "Jack". Examples of Napier include: