Watch Alien Abyss

The team enlists special equipment in an epic search for two large air force planes that vanished without a trace with dozens of people on board. Despite a massive search, nothing was ever found. Are planes colliding with mysterious UAPs that are now acknowledged as fact by the US Navy? To investigate, the team embarks on one of its most harrowing dives yet, battling extreme depths and currents that threaten to sweep them away.

Explore the bizarre mating rituals of the ocean's most peculiar creatures, from bloody battles to super-size litters.

Discover some of the planet's strangest animals, from snapping shrimp to wolf eels, and see how these ocean-dwelling creatures ensure mutual survival.

Meet the oddballs of the oceans and witness the remarkable skills they have built over the years, from blind worms who fish to crabs who climb trees and more.