Killing Time

Summary
From the back cover: Second History: A Romulan time-tampering project that has transported the Enterprise and the galaxy into an alternate dimension of reality. Now Kirk is an embittered young ensign and Spock is a besieged starship commander.

Lured into a Romulan trap, Captain Spock and Ensign Kirk must free themselves from both their captors and their own altered selves...before the galaxy hurtles toward total destruction!