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!