Web of the Romulans

Summary
From the back cover: Ravaged by a killer virus, the Romulans enter Canara, where the only antidote can be found. Desperate, they incite a victorious Enterprise attack on one of their vessels - but Kirk discovers their ruse.

Meanwhile, the central computer has fallen in love with him, severely crippling the Enterprise. Now Kirk must bring the antidote to the Romulans - before the galaxy crashes over the brink of war!