The Grand Nagus Zek arrives on DS9 to visit Quark. He compliments Quark for having the foresight to establish his bar at the mouth of the wormhole. When Krax, Zek's son, protests that Quark had no idea that there was a wormhole, Zek responds: "That's what makes it so impressive!"

Zek calls a meeting to discuss Ferengi business interests–in particular, expansion into the Gamma Quadrant, where no one knows to be wary of Ferengi. At the meeting, he announces that he is getting old, and isn't as greedy as he used to be, so he appoints Quark as the new Grand Nagus. Later, while giving Quark advice, Zek dies.

There is an attempt on Quark's life, which turns out to have been planned by Krax along with Quark's brother, Rom. A second attempt by the two also fails, and Zek reveals that his death was a ruse, and it was all a test to see if Krax was ready to succeed him as Nagus–a test Krax failed miserably.

In the B-plot, Sisko is worried about Jake being friends with Nog. Rom forbids Nog to go to school after the Nagus expresses concern about him wasting his time in a human school, and Nagus and Jake have a brief falling out, but they soon get back together. In the end, when Sisko goes to find Jake, who has not returned on time for dinner, he finds the two of them together–Jake teaching Nog to read.

As a story, this isn't much, but it's good to give Quark an outing, and it works well as comedy–Zek is excellent. And the story with Jake and Nog is good, too.

Notes

This is the first mention of The Rules of Acquisition. Rule 1: "Once you have their money, you never give it back." Rule 6: "Never let family stand in the way of opportunity."

Jake is teaching Nog to read, but how? They almost certainly don't share a language. I guess "now try reading this" with verbal feedback and letting the universal translator handle the details may be enough.