Odo's having back problems. Bashir says it's a pinched nerve from sitting too straight. Quark turns up to irritate them both and also show off the baby Changeling he bought from a trader. Odo says it's sick and buys it off him. Bashir sets about curing it. Odo wants to bring it up, and Sisko suggests bringing in Doctor Mora, the scientist who originally raised Odo.
Also, apparently Kira's gone into labour. Bashir excuses himself while Odo chats with his own baby. While Kira tries to relax, the O'Briens and another Bajoran stand by playing musical instruments. Shakaar arrives to help.
Odo takes the baby Changeling to the bar and talks to it, much to Worf's confusion. Back in his quarters, Odo pours the baby into a tray. He's surprised when Mora turns up to help and resists the doctor's attempts to help. Odo's still bitter about the methods Mora used to get him to shape-shift in the first place. Mora ends up staying in a capacity as observer.
Kira still hasn't had the O'Briens' baby. Apparently she couldn't relax enough.
Odo shows the Changeling baby various shapes to try to get it to shape-shift. Mora measures its volume and says it hasn't grown much. The pair argue about Mora's methods and then realise that Sisko has been watching them. Sisko says Star Fleet wants them to establish communications with the baby, or Star Fleet will want to take over the project. Mora suggests maybe it's time to start using his methods. Using a mild electric charge, they manage to get the baby to move finally.
While O'Brien and Shakaar argue over Kira, she goes into labour again.
The experiments on the Changeling baby continue, with Odo starting to realise that maybe Mora isn't that evil after all. The baby morphs a face, much to their delight. Mora says that Odo's formed a connection with the baby. They have champagne.
Back in the B-plot? No baby yet. O'Brien and Shakaar argue over whether O'Brien's allowed to see the birth, and Kira kicks them out.
Quark finds Odo raiding his bar and is made extremely nervous by Odo's good mood. The computer alerts Odo to strange activity in the lab - the baby's dying. Bashir and Mora struggle to save it.
In the B-plot, Kira is finally having the damn baby, and says Shakaar and O'Brien can come back in if they promise to behave. Baby pops out and everyone is happy. The end.
Meanwhile, Odo holds the dying Changeling baby in his hands, and it absorbs into him, restoring his shapeshifting ability in a matter of seconds. Trek science, thou art dodgy.
Shakaar farewells Kira and Odo farewells Mora, the pair having come to a better understanding. Kira confides to Odo that she wants a baby.