Karen Lloyd: The mysterious microbes living deep inside the earth -- and how they could help humanity

The ground beneath your feet is home to a massive, mysterious world of microbes — some of which have been in the earth's crust for hundreds of thousands of years. What's it like down there? Take a trip to the volcanoes and hot springs of Costa Rica as microbiologist Karen Lloyd shines a light on these subterranean organisms and shows how they could have a profound impact on life up here.