We hear from Magnus Carlsen, who in 2014, became the first player ever to win all three world chess titles in one year, achieving the highest official rating of any player in history.

Woman grandmaster, three times British champion and chess historian, Yao Lan is our guest. She talks about the origin of chess.

In the 1970s and 80s, scientists in Russia, managed to dig a hole more than 12,000 metres deep. It was called the Kola Superdeep Borehole. One of the geophysicists involved tells us about the deepest man-made hole in the world.

Plus, one of the most controversial political scandals in modern US history, the Iran-Contra affair. And from 2010, the first HIV positive passenger to travel legally to the US after a 22-year ban.

Finally, the story behind the BBC's Strictly Come Dancing tv show.

Contributors:

Magnus Carlsen - chess grandmaster and five-time World Chess Champion

Yao Lan - chess woman grandmaster, three times British champion and chess historian.

Professor David Smythe – geophysicist.

Clemens Ruland – first HIV positive passenger to travel legally to the US after a 22-year ban.

Karen Smith - co-creator and executive producer Strictly Come Dancing.

(Photo: Magnus Carlsen in 2014. Credit: Francois Nel/Getty Images)