An unputdownable Star Trek adventure following Spock as he must face the Romulans before they destroy the Guardian of Forever.

The Romulans attack the planet Gateway, where Federation scientists are studying the Guardian of Forever—the mysterious portal to the past. Captain Kirk and the crew of the USS Enterprise must protect the Guardian or destroy it. But Spock has already used the portal to journey to the past. On the planet Sarpedion, 5,000 years ago, Spock knew a beautiful, primitive woman. Now he has gone back to meet his son at the risk of being lost to time forever.