Plot summary
The Enterprise welcomes aboard Dr. Leah Brahms, a lead designer of the Galaxy -class starship engines. Chief Engineer Geordi La Forge, who also had previously used a lifelike holodeck simulation of Brahms to help save the Enterprise in " Booby Trap ", is excited to meet her, but is frustrated when she complains about modifications he has made to the engines of the Enterprise. La Forge also learns that Brahms is married, a fact not noted in the holodeck simulation. Brahms learns how La Forge previously saved the Enterprise, and asks another crewman to show her the simulation. Alarmed, La Forge tries to stop her but is too late. Brahms discovers the holodeck simulation and accuses La Forge of invading her privacy.
Meanwhile, the Enterprise is attacked by a strange space-faring creature that is nearly the size of the ship. Taking defensive action, Captain Picard orders a low-power phaser burst on the creature, inadvertently killing it. Scanning the creature, Data finds another smaller entity inside of it, and the crew realizes the larger creature only attacked to protect its unborn. The crew performs a Cesarean section, using the ship's phasers as a scalpel to free the newborn. As the ship turns to leave, the newborn attaches itself to the ship and begins feeding off its power systems, imprinting on the Enterprise as if it were the creature's mother. As the ship's power supplies run low, the crew finds a nearby debris field toward which the larger creature appeared to have been traveling, and realize it would serve as a better feeding ground for the infant.
After the crew arrives at the debris field on the last of the ship's power reserves, they find they are unable to dislodge the creature. Worse, they also discover the creature is emitting radio signals attracting more of its kind from the debris field, and they are heading straight toward the Enterprise. La Forge and Brahms put aside their differences and devise a solution: altering the frequency of energy to "sour the milk", causing the infant to leave the ship and join the other creatures. As the Enterprise' s power is restored, La Forge and Brahms make up and determine they can still be friends.
Credits
Adapted from Wikipedia contributors, Galaxy's Child. Paragraphs and formatting adjusted; illustrations, reference markers, block quotations and non-story material omitted.