The mood aboard Deep Space 9 has grown dark as the Dominion threat has intensified. Three ships have disappeared along the Cardassian border in just the last three weeks, Odo has canceled a vacation due to increased thefts of food rations and medical supplies, and the crew is generally gloomy - Captain Sisko most of all. What's more, Kai Winn Adami announces she'll be visiting the station. Fortunately, Jake Sisko has a plan to lift his father's spirits - Quark has invited him to an auction at which a mint-condition Willie Mays rookie year baseball card will be available. He'll show up, purchase the card, and make a gift of it. "How hard can that be?"
Jake convinces Nog to let him use some of the gold-pressed latinum he's saved up over his lifetime so he can purchase this gift for the Captain, but even Nog's entire life savings isn't enough to out-bid a mysterious man at the back of the room. He bids 10 bars of latinum (twice what Nog has saved) and then disappears out the back. Nog tries to convince Jake they've lost the card, but Jake is determined to come through for his father. They intercept the man as he leaves the auction house but he mutters something about refusing to get involved with any "soulless minions of orthodoxy" and disappears into a turbolift.
Kai Winn, meanwhile, has revealed that the Dominion has requested a meeting with her, and Weyoun arrives to discuss business. Both Sisko and the Kai are concerned about how Bajor will be able to cope with a pending Dominion invasion.
Dr. Elias Giger, the man who bought the baseball card, requests a meeting with Jake and Nog after learning of their relationships to Captain Sisko and Quark. It seems he needs some supplies he believes they're in a position to obtain, and he's willing to trade the baseball card for those supplies. Jake agrees, even after learning that Dr. Giger plans to use the supplies in the construction of his cellular regeneration and entertainment chamber - a device designed to keep the cells of the body from getting bored, thus prolonging life indefinitely. Jake and Nog agree that the man is crazy, but since he has the baseball card they have little choice.
Giger provides a lengthy list, and Jake and Nog go straight to work. For a neodymium power cell from a Cardassian phase-coil inverter they visit Chief O'Brien, but he's too busy recalibrating EPS regulators to help. Nog, always a Ferengi, strikes a deal: Jake and Nog will do the work while the Chief visits a holosuite for a chance to go kayaking for the first time in weeks. In exchange, O'Brien will find the power cell.
For five liters of anaerobic metabolites suspended in a hydrosaline solution, they call on Doctor Bashir, who's not only busy but is doing something he wants to do. Nog's cunning though, and he gets Bashir to admit that he'd be much happier if he had Kukalaka - his teddy bear. The pair manage to retrieve the bear from Leeta while she's sleeping.
While Jake and Nog are running errands, Kai Winn discusses Weyoun's proposal with Sisko. The Dominion wants to sign a non-aggression treaty with Bajor. She recognizes that Starfleet can't possibly protect Bajor from the full strength of the Dominion, but also knows that allying with the Dominion could make Bajor the next world conquered. Sisko advises that she stall for time and keep Bajor's options open. Weyoun, meanwhile, has gotten suspicious of the activity in the quarters below his, where Giger's machinery are humming along.
Nog has agreed to filter out subharmonic distortions from Worf's Klingon opera recordings while Jake helps Kira with an upcoming speech. When they've collected the last of the supplies, however, they find that Giger is no longer in his quarters. And Odo insists there never was such a person in those quarters. When he hears about the "Cellular Regeneration and Entertainment Chamber," he reads them a list of charges and scares them out of his office.
Searching for an explanation, Jake blames Kai Winn, thinking she was after a Bajoran mandolin that was auctioned in the same lot as the baseball card. He and Jake confront her in the corridor as Weyoun departs. Sisko is furious when he finds out, but Jake, still wanting to surprise his father, lies and insists that he and Nog got drunk at Quark's before approaching the Kai. Naturally this makes Captain Sisko even more furious, and he tells them that he was wrong to place so much trust in them. He confines both of them to quarters and angrily dismisses them.
As the two argue after they leave Sisko's office, they're suddenly beamed onto Weyoun's ship. He inquires about their connection to Dr. Giger, who was abducted on Weyoun's orders. Jake explains that they were only trying to acquire a baseball card, but Weyoun doesn't believe him. When Jake concocts an absurd story about hunting for a mysterious man from the future named Willie Mays, Weyoun realizes their original story was truthful and releases them - with the baseball card.