While Troi expresses concern that Salia and Anya may not be exactly what they appear to be (i.e. humanoid), Geordi sends Wesley out of Engineering until his hormones calm down. Wes consults with Worf, Data, and Riker about what to say to Salia, but none are particularly helpful. While Anya (whom we've seen change her shape earlier) takes a tour of the ship, Wes lurks outside Salia's door, until she asks him in to find out how to work the food dispenser.
Anya, meanwhile, is acting overly paranoid with respect to Salia's safety. When she sees Geordi is making repairs, she demands to know exactly what the problem is, and says she'll be back to check his progress. Worse yet, when she sees someone in Sickbay with a contagious disease, she insists he be killed. When Pulaski refuses, Anya changes shape into a hideous monster and tries to do it herself, but is stopped (more or less) by Worf and assumes her original shape. Picard confines her to quarters, but confesses there may be a problem if Anya changes shape again.
Meanwhile, Wes has shown Salia many worlds in the holodeck, and is now eating with her in Ten-Forward. She becomes depressed that she will probably never leave Daled Four once they arrive. (It is hoped that her leadership will unite two warring factions, since she is a child of both, but it's also a full-time job.) When Wes naively suggests staying on the Enterprise, she bursts into tears and leaves. Wes follows, but then the two are separated by Picard and Anya, who's already noticed Salia's gone.
As the ship departs for Daled Four (since Geordi's done with his repairs), Picard explains to Wes that Anya's a shape-changer (allasomorph) and very dangerous. Wes promises to stay away from her, but allows Salia in when she sneaks out of her room while Anya's sleeping. The two kiss, but are interrupted by Anya, again as a monster. To Wes's shock, Salia then changes form herself, into something even worse.
The ship arrives at Daled Four, and Anya tells Salia that her task as protector is over, and she is not coming to the planet, but returning to her home. When Salia comes to Wes's quarters to say goodbye, however, Wes is angry and hurt, and asks Salia to leave. However, as she prepares to beam down, he brings her some Thalian chocolate mousse as "a taste to remember me by." He watches her assume her natural form, one of wondrous light, and then goes to Ten- Forward, where Guinan comforts him.