A spectacular fossil graveyard reveals a 43-million-year-old whale that had four legs and could walk. Follow scientists as they search for new clues to how mammals moved from land into the sea to become the largest animals on Earth.

Join scientists on the biggest Arctic research expedition of all time. Facing hungry polar bears, perilous sea ice cracks, and brutal cold, the team strives to understand the forces that are changing the region—and the world—forever.

Many descendants of enslaved people have little record of their family's ancestry. Follow one family's quest to discover their lost history, and see how science and genealogy can help rebuild a family tree broken by slavery. Join filmmaker Byron Hurt at his extended family reunion as they celebrate the joy of family in the African diaspora and discover new details of their history.