Grand Nagus Zek arrives on the station and shows Quark and Rom a copy of his new project: he has rewritten the Rules of Acquisition. In the new and improved book, Zek encourages Ferengi everywhere to turn from greed and profit and concentrate on kindness and giving. In short, he wants to eliminate all of the selfishness that Ferengi hold dear.
Zek goes on to add that he has brought the Bajorans a gift: one of the orbs. The orbs are the most sacred objects of the Bajorans, and Quark cannot imagine where the Nagus could have gotten one. When Quark is exposed to the orb, he has a vision in which Zek states that the New Rules of Acquisition are a "gift" as well. When he sees that Zek visited the Wormhole before arriving at the station, he believes that the wormhole aliens changed Zek and gave him the ideas for the New Rules.
Quark takes Zek back to the Wormhole to ask the aliens what they did to the Nagus. The aliens reply that they were so disturbed by the sheer selfishness of the Nagus that they de-evolved him. When Quark promises never to expose the wormhole aliens to another Ferengi, they agree to restore Zek to his normal, greedy self.
The other plot involves Bashir being nominated for a medical award which he ends up not winning.