The crew answers a distress call from a small spacecraft and beams its occupant into Sickbay. The severely ill Vidiian female is dying from the Phage, which has ravaged her people. The Doctor puts her decaying body into stasis and transfers her synaptic patterns into Sickbay's holobuffer. He then creates a holographic body that reflects the way the female would look if she were not afflicted with the Phage.
The astonished patient revives and introduces herself as Dr. Danara Pel, a hematologist. She's grateful for what the Doctor has done for her, but he admits it is just a temporary fix. She can't survive in this form; he still has hopes of treating her ravaged physical body.
Embittered by her own harrowing experience as a prisoner of the Vidiians, Torres balks at the Doctor's request that she donate some of her brain tissue to help Pel, since Klingon DNA is resistant to the Phage. But after advising her that it's Pel's only chance, she relents, and he grafts the tissue onto the Vidiian's brain. It'll be several days before they know if the graft will take, so the Doctor and Pel begin spending a lot of time together.
The Doctor is confused by his affection for Pel, but Kes urges him to tell the woman how he feels. Yet when the Doctor blurts out his interest in Pel, she says she'd prefer to keep their relationship strictly professional. While the disappointed Doctor seeks Paris' dating advice, Kes gets Pel to admit she really does like the Doctor. Later, Paris tells the Doctor he knows the perfect romantic getaway to impress Pel, and using Paris' holodeck program, the Doctor has a lovely date with Pel in a 1957 Chevy.
Not long after, the Doctor is shocked to discover that Pel's brain is rejecting the graft. He doesn't understand what could have gone wrong. Pel admits she sabotaged her medical treatment because she doesn't want to return to her diseased body, despite the fact that the alternative is death. The Doctor convinces her that he will love her no matter what she looks like, and convinces her to survive and go on caring for her sick compatriots. As Voyager heads for her home, she and the Doctor share a tender dance in Sandrine's bar.