Two non-corporeal Organians possess the bodies of various crew members to observe humanity's reaction to tragedy. The curious beings study the response of the Enterprise crew to a fatal silicon-based viral infection contracted by Trip and Hoshi during an away mission. Phlox works feverishly for a cure. Will the "advanced" aliens learn anything about human empathy and compassion? 

Archer tries to unify the Andorians, Tellarites, and Vulcans in a plan to capture a remote-controlled Romulan marauder ship threatening to destabilize the region. But, a desire for vengeance interferes with Archer's attempts to ally Shran and the Tellarites, where Archer and Shran fight to the death, almost. Trip and Reed probe the inner workings of the unmanned Romulan warship and must outwit their captors to escape.