Miles and Julian are about to do their usual, Defend the Alamo, and are visiting Vic in the Show Lounge in order to invite him to join them there, when, suddenly, things go awry and the Casino is taken over by an old rival of Vic's, with mob connections. For reasons I won't go into, the program can't simply be reset, and Vic is tossed out. DS9's senior staff, plus Jake, Nog, and Kasidy, most of whom are good friends with Vic, decide to help him out.
Julian, after consulting with the friend who created the Vic program, reveals that this is a "jack in the box", a kicker intentionally put into the program to keep things unstable and interesting. To set things right, the rival must be eliminated. Problem is, he must be eliminated within the constraints of the 1960-era rules, and the rival is "made", so he can't just be killed.
Sisko becomes fairly annoyed with his staff, who are all off helping Vic, and ignoring their day to day work, until, eventually, he gives in and joins them.
What ensues is an homage to "Ocean's Eleven", as they create a clockwork plan to rob the casino's vaults and get Vic's rival in hot water with his capo.
In a fun final touch, Sisko and Vic perform a duet of "The Best Is Yet To Come"!