Bertie and the team cross the infamous Drake Passage, the roughest stretch of ocean on Earth, to reach Antarctica, where they witness and film the staggering intelligence and adaptability of a group of killer whales. Known as B1’s, they use an extraordinary strategy to hunt seals resting on ice. Working as a team, they create a powerful wave to push the seals into the water. Bertie wants to find out why the B1 population is declining and film the other surprising ways they catch prey in their rapidly changing world.