The Best Episodes Directed By Duncan Singh

When Earth first formed from clouds of dust and gas 4.6 billion years ago, it was - like so many other lifeless worlds in the universe - devoid of an atmosphere, an inhospitable rock floating in the black void of space. But as the young planet is pummelled by asteroids, a period of extraordinary upheaval begins.

The Aztecs battle to save their civilisation from Spanish invaders – but is the real threat from the enemy within?