The sources document an intense crisis aboard the USS Enterprise, centered around a Vulcan scientist named Skel who is unknowingly carrying an alien infection within him that drove his father to murder years ago. This contagious, mind-altering entity resides in ancient artifacts Skel studies and is responsible for his abduction by Ferengi, as well as the rising violence and unusual behavior among the Enterprise crew, including Dr. Crusher, Commander Riker, and Geordi La Forge. Counselor Troi, whose empathic abilities are severely affected by the entities, teams up with Worf, Data, and scientist Dr. Dannelke to create a device to lure the entities out of their hosts and prevent the infection from spreading further, particularly to an incoming Vulcan ship. Ultimately, the crew cures the infected, contains the artifacts, and reveals that Skel's mother, T'Reth, had preserved her katra (consciousness) within her son to protect him.