"Leah is changed. Months earlier, she left for a routine expedition, only this time her submarine sank to the sea floor. When she finally surfaces and returns home, her wife Miri knows that something is wrong. Barely eating and lost in her thoughts, Leah rotates between rooms in their apartment, running the taps morning and night. As Miri searches for answers, desperate to understand what happened below the water, she must face the possibility that...

While mapping the ancient underwater city of Marinth in the Atlantic Ocean, submersible designer Hannah Bryson makes a shocking discovery: she may have finally uncovered the truth about the once-glorious city's mysterious demise. Long ago it was a thriving metropolis bursting with culture and life- Marinth's sudden disappearance has plagued scientists for years. But now, with her unexpected new findings, Hannah realizes that the ancient city's explosive...

"To stop the world from burning, it's up to Sigma Force to uncover a secret buried at the heart of our planet. The Titan Project-an international research station off the coast of Australia-discovers a thriving zone of life in an otherwise dead sea. The area teems with a strange bioluminescent coral that defies science, yet holds great promise for the future. But the loss of a military submarine in the area triggers a brutal attack and sets in motion...