The endlessly fascinating orca is the most powerful predator of the sea. Called a killer, it is also remarkably graceful and highly intelligent.

A radical researcher, activist and visionary, Dr. Paul Spong believes orcas can be understood only in the wild. He and his crew of volunteers from around the world follow whales with cameras and a network of underwater microphones, monitoring their amazing behaviour.

Orcas, the most closely bonded animals on earth, stay with their families for life. For over 25 years, Dr. Spong has fought to release Corky, a performing orca held captive in California, to return her to her family in the waters of the Pacific.