Hector Berrellez identifies the mysterious Cuban who interrogated Kiki Camarena: a veteran CIA operative, Felix Rodriguez, a key figure in the Iran-Contra scandal. Although warned not to take his investigation further, Hector refuses and is eventually forced into retirement. The case languishes for years, and then a new source comes forward with a shocking allegation.

We all come from the same place, a moment when a dead rock came to life. Discover the story of how and why life began on Earth, and what makes our planet different from the others.

Foo Fighters prepare to record at the Austin City Limits Studio, with blues guitarist Gary Clark, Jr. In this episode is examined the roots of Austin's music scene, with interviews featuring Billy Gibbons from ZZ Top, and Roky Erickson from 13th Floor Elevators, who is considered one of the American fathers of psychedelic rock. Dave also chats with Terry Lickona, the executive producer of Austin City Limits. The song 'What Did I Do? / God As My Witness' is recorded during this chapter.

Scientists have no idea what it is, but Dark Matter and Dark Energy make up 96% of the Universe. Dark Matter is everywhere. It passes through everything we know on earth at billions of particles every second, yet no one has ever gotten a direct detection of this mysterious dark substance. An even more bewildering force is Dark Energy, which is rapidly pushing apart our Universe. Discovered only ten years ago, scientists are struggling to comprehend its unusual characteristics and answer the ultimate question; what is the fate of our Universe? Using cutting-edge computer graphics watch as the universe is brought down to earth.

The Roman army turns its attention to an island of rich resources, powerful tribes and druids, and advanced military equipment - Britain. This episode tells the story of the Celts' last stand against the Roman army - a revolt led by another great leader, the warrior queen Boudicca.

What makes us human is the squishy triple-pounder inside our heads. It lets us build skyscrapers, and lift a special few of us into space. We are the only species on this planet that can construct realities in our mind and then go actually build it. The story of how our mind evolved on this one strange rock is one of chance, coincidence and impossible odds.
This episode is an investigation into the mystery of the human brain and the chain of events that produced the anomaly of human intelligence.