The Enterprise stops at Starbase 313 to pick up some scientific equipment, and Geordi has the pleasure of welcoming on board Dr. Leah Brahms, whose image he fell in love with on the holodeck, and who is coming on board specifically to talk to him. He's ecstatic about finally meeting "his dream", but the ecstasy sours when Leah greets him as "the one who's fouled up my engine designs."

As the Enterprise diverts to investigate some interesting radiation readings, Geordi and Leah's relationship goes further downhill. His justifications of his many modifications (that theory doesn't equal reality, mainly) are met with a cold shoulder, and Geordi's repeated slips about things he assumes Leah knows and things he does know about her make her rather uneasy. This comes to a head when Geordi sets the stage for a textbook seduction in his quarters, but Leah is still mostly business and doesn't stay long.

Meanwhile, the Enterprise encounters the source of the strange radiation-a space-born lifeform. Unfortunately, it attacks them, and the only way they save themselves is with a minimal phaser burst which kills the creature. Picard is thunderstruck at what he's been forced to do, and very depressed, but before he leaves the bridge, Data picks up some new readings from the creature...indications of a separate, smaller entity inside. "No wonder it attacked us..." says Picard. "It was about to give birth!"

As the bridge crew, on Bev's advice and over Worf's objections, prepare to help the child's birth by using the phasers to give a Caesarean section, Leah finally asks Geordi about his odd attitude towards her. He tells her that he's admired her (though not about the holodeck), and that he hopes they can become good friends- and she's flattered, but surprised that Geordi doesn't already know that she's married. A rather bitter Geordi rails about how wrong the computer was to Guinan, until she brusquely points out that all Leah's done is failed to live up to his false expectations.

The Caesarean, in the meantime, is successful, and the baby is born. The Enterprise prepares to leave, but before it can do so, the baby follows and attaches itself to the ship. Apparently, it's imprinted-on the Enterprise, and it begins to drain the ship's energy. After a brief conference where it's decided to head for wherever the mother was probably heading and then blow the baby off (by depressurizing the shuttle bay it's right over), Leah asks Geordi if she can take a look at a file of all the modifications he's made. He rushes off to the bridge, but she looks at the file-and then heads, unknowing, for the very holodeck simulation Geordi fell in love with Leah in. Geordi hears about this too late, and enters just in time to greet a very angry Leah who feels invaded and used. Geordi eventually calms her down (or at least quiets her down) and angrily claims that the only thing he's guilty of is offering her friendship.

The ship reaches the mother's destination-an asteroid belt made up of those elements the creature needs to survive. Unfortunately, blowing off the creature fails, succeeding only in draining power much further and in making the baby call its relatives for help. Eventually, Leah and Geordi, by working together, reason that by changing the auxiliary power away from the frequency the creature is used to, they might "sour the milk." It works in the nick of time, and Geordi and Leah each realize that the "real" people aren't so bad.