From the back of the book: You're an ensign in the Starfeet and you've been assigned to the Enterprise! With Captain Kirk and Mr. Spock, you'll explore amazing new worlds. You might rescue an alien race from a deadly disease, or do battle with a Klingon spy, or time travel to another unniverse. If you make the right choices, you could be a hero and save the Enterprise. But be careful - or you, Captain Kirk and Mr. Spock could all be in terrible danger!