For decades, rumors have swirled about massive,15 to 20-foot mako sharks patrolling the deep waters off Southern California. Long dismissed as fishermen's tales, new footage, along with a recently published photo capturing a mako that appears to push 15 feet, is now forcing scientists to rethink everything they know about these oceanic apex predators. Marine biologist Tristan Guttridge, alongside conservationist Kendyl Berna and shark tagger Keith Poe, leads an investigation to determine whether the world's biggest mako is real - and hunting in the coastal waters of Santa Catalina.

For millennia, the great white shark has reigned as the ocean's ultimate apex predator. But now, a new challenger is emerging: the killer whale. Around the world, sharks are washing ashore with their livers removed with chilling precision while in the Strait of Gibraltar, orcas are targeting sailboats - ramming hulls, crippling rudders, and sinking vessels. To investigate this alarming shift in behavior, Dr. Tristan Guttridge places himself directly in the path of an orca encounter, using their attacks on boats to reveal how these predators hunt and ultimately, how they may be taking down great white sharks.