Star Trek Adventures Series / Spock, Messiah! / Theodore R. Cogswell, Charles A Spano Jr.

A defective mind link turns the logical Mr. Spock into a fiery revolutionary who sets out to convert the planet Kryos with fire, sword and a forbidden philosophy. Captain Kirk and the Enterprise crew must summon all their skill and cunning in a race against time on a hostile planet. Can they destroy the fiendish mind that holds Spock captive before it destroys them?