Neil works with a team of scientists and marine mammal toxicologists on an expedition to prove the presence of deadly toxins inside Bermuda’s mid-migratory humpback whales. Follow Neil and his team into the danger zone as they get up close and personal with 50 tonne humpbacks, collecting biopsy samples using an adapted compound bow. Watch Neil and his team swim with these ocean giants in a mesmerising and magical sequence as Neil comes face to face with one of the most intelligent mammals in the ocean. The team also deploy their aerial drone to observe a mother humpback and calf, and Choy has a dangerous encounter when he receives a report of a dead sperm whale being torn to shreds by hungry sharks. Narrated by Michael Douglas