More than 30 years ago, Robert Swan became the first man to walk to both the North and South Poles. In 2017, he found himself back on the ice, trekking 600 miles across Antarctica with his son, Barney. But this time, the duo set out to complete the first-ever expedition to the South Pole using solely renewable energy. Their mission: prove that if these technologies can work in the harshest environment on Earth, they can work in our everyday lives. Along the way, they faced unexpected obstacles that threatened to claim Barney's limb -- and Robert's life.