Kirk and McCoy accompany Spock to the Vulcan Academy Hospital seeking experimental treatment for a badly wounded Enterprise crew member. Spock's mother is also a patient in the hospital, and Kirk soon becomes involved in the complex drama of Spock's family...

Suddenly, patients are dying, and Kirk suspects the unthinkable -- murder on Vulcan! But can he convince the Vulcans that something as illogical as murder is possible? Until the Killer is caught, everyone is in danger!