Inside Bill's Brain: Decoding Bill Gates Limited Series: Episode Guide & Ratings

Bill Gates speaks about his life-or-death mission to get better sanitation to the developing world. Also, his sisters share their childhood memories.

The connections that shaped Bill's life come into focus, including a childhood friendship and his unique bond with Microsoft co-founder Paul Allen.

The search for climate change solutions requires passion, resources and a sense of urgency -- three qualities Bill Gates clearly possesses.