The Enterprise is summoned to transport a dangerous criminal from Starbase prison to a rehabilitation center: brilliant physicist Dr. Georges Mordeauxs, accused of promising to send people back in time -- then killing them instead.

But there's more at stake than just a few lives. For Mordeaux's experiments have somehow throw the entire universe into a deadly time warp. All of existence is closing in on itself -- and only Spock can stop The Entropy Effect!

The Starship Enterprise¿ is summoned to transport a dangerous criminal to rehabilitation: the brilliant physicist, Dr. Georges Mordreaux, who is accused of promising to send people back in time, then killing them instead. But when a crazed Mordreaux escapes, he inexplicably bursts onto the bridge and murders Captain Kirk before the crew's eyes. Now Spock must journey back in time to avert the disaster before it occurs. But more is at stake than Kirk's life. Mordreaux's experiments have thrown the universe into chaos, and Spock is fighting time itself to keep the very fabric of reality from unravelin