Calypso

In 1966, a team of scientists that includes engineers and historians is sent to an underwater base in order to study ancient, submerged ruins whose existence could throw the chronology of human history into chaos. After a series of potentially-deadly mishaps, the team encounters an enigmatic, yet seemingly-benevolent entity that appears to be guarding a secret that could change the world forever.

And determine how far they're willing to go to protect her.

Or destroy her.