Shark Week's Paul de Gelder teams up with Dr. Mark Meekan to travel to the sharkiest places in the world, Cobourg Penninsula in Northern Australia. They want to know what happens when 14-foot crocodiles moves into shark infested waters?

Early November, pregnant giant hammerheads arrive off Bimini, in the Bahamas and Shark Week's Dr. Tristan Guttridge wants to know why? And he and his team even perform the world's first ever ultrasound on hammerheads to find the answers.

Greg Skomal & Joe Remeiro return to Shark Week to study the area that brings thirty species of sharks, the Gulf Stream. They will focus on three sharks that can out-swim, out-think, and out-compete all the others makos, great whites, and porbeagles.