In the side plot, Voyager arrives to meet with Vostigye scientists aboard their station, but finds that the station has been destroyed by unknown causes. They discover a nearby subspace anomaly, likely responsible for the destruction, that is growing in intensity, and Janeway orders the ship to leave. They are suddenly hit by a massive energy wave from the anomaly that disappears just as quickly. The crew determines the anomaly is an eddy between space and subspace, and to be able to move away safely, they must determine when it will next appear. They launch a probe into the anomaly, finding it has a stable center like an eye of a storm and rich in energy they could use to power Voyager.

A plan is crafted to have Tom Paris use a shuttle to get close to the anomaly and collect the energy in the anomaly's waste, as Voyager's engines appear to be disrupting the anomaly. When Paris gets close, he suddenly disappears into the anomaly. Though injured and suffering effects of being in subspace, Paris is able to still transmit to Voyager helping to identify the structure of the anomaly as an interfold between space and subspace. With this information, Voyager's crew is able to help Paris ride the eddy back into normal space, where he is quickly transported to Sickbay and treated back to health by The Doctor .

The main plot of the episode centers on the Doctor. To help him explore what it means to be human, he has created a virtual family for himself in a holodeck simulation, consisting of his wife Charlene and two children Jeffrey and Belle. The Doctor invites B'Elanna Torres and Kes and for dinner, where the two find the family to be far too perfect. Torres offers to make changes to the program to introduce realistic elements to his family. Once completed, the Doctor finds Charlene too busy to take care of the children, and he must manage Jeffrey's involvement with Klingon teenagers and Belle's desire to play the dangerous game of Parrises Squares. The Doctor is troubled by these changes but stays with the program.

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Wikipedia