All Those Who Wander

The Enterprise is en route to space station Deep Space K–Seven when it receives another priority assignment to investigate the missing USS Peregrine. While the Enterprise continues to K–Seven, Pike leads an away team to an ice planet where they find the grounded Peregrine. Hemmer and Uhura restore the ship's systems while Pike learns that it was carrying three refugees and one was infected with Gorn eggs. These hatched, and the hatchlings burst from his body and attacked the crew. Pike's team finds the other two refugees, who are the only survivors. One of them, Buckley, is also infected with Gorn eggs and the hatchlings burst out. They attack the team but they also fight each other until only the strongest hatchling is left. The team form a plan to kill the hatchling using cold temperatures from the ship's environment controls, but not before Hemmer is infected.

Summary from Wikipedia, CC BY-SA 4.0.