The Rift reappears…

The Chinese Government learns of its existence… and the existence of aliens in the distant past.

They send a Chinese submarine through the rift in order to bring back the alien technology.

To bring them back, the United States sends the crew of the USS Orca through the rift. However, they find themselves sixty-four million years in the past—with a new unknown threat. The aliens who they thought they had stopped before are putting in place an alternative plan to invade the future and dominate the planet.

Not only does the crew have to deal with the Chinese submarine, but they also have to battle prehistoric creatures on land and the ocean, some never known to ever exist, in order to stop the alien threat and hopefully return home before the rift closes trapping them in the past forever.