Odo returns from a conference with an unexpected guest: a Changeling who tracked and boarded his runabout. Odo recognizes him as one of "the hundred" shapeshifters who were, like himself, sent out as infants into the galaxy to learn about other species. Back at the station, Sisko warily releases the visitor to Odo's custody. The Changeling, known as Laas, queries Odo about their unique species — with which Laas has made no contact since his infancy — and "the Link," a Changeling ritual that allows shapeshifters to meld with one another and thereby form a single, sentient collective entity.

After Odo informs Kira that he has linked with Laas, Kira, worried that Laas may be a Founder intending to lure Odo back to the Dominion ranks, asks to meet him. Odo introduces Laas to Kira, Bashir, Ezri and O'Brien. Unfortunately, Laas mistrusts humanoids, insisting to Odo that, in all of his prior encounters, they have been intolerant of shapeshifters, and he consequently treats the four with blatant hostility. Privately, Laas urges Odo to join him in seeking out "the hundred" to form a new Link that will allow them to live freely as Changelings.

When Odo recounts the conversation with Kira, she's troubled by the fact that Odo didn't refuse Laas' offer outright, though Odo assures her he's happy, and decides he will stay. Later, after being harassed for changing form in public, Laas argues heatedly with a pair of Klingons who brutally attack him. Angered and defensive, Laas fatally stabs one of them.

Odo learns that the Klingons plan to prosecute Laas for the murder. He suspects the case is driven by anti-Changeling prejudice, and protests that Laas will never get a fair trial. When Odo visits Laas in his holding cell, the Changeling taunts Odo by claiming that he is accepted by his friends only because he has assumed their form. Talking with Kira, Odo admits that he sometimes wonders what it might be like to live among his own people. Wanting Odo to be happy, Kira allows Laas to escape from his cell.

While Sisko orders a massive search for the fugitive, Kira tells Odo where he can find Laas. Odo goes to Laas' hiding place, but to the Changeling's dismay, Odo explains that he's not going with him because he loves Kira. Laas departs alone to continue his search, and Odo returns to Kira's waiting arms.