Al Capone moves back to Chicago and takes over two floors of the city's finest hotel, the Lexington. With a thriving business and Chicago politicians in his back pocket, Capone soon reaches a level of celebrity normally reserved for athletes and entertainers. As Capone's profile grows, he begins to indulge in all that the Roaring '20s have to offer, including cocaine. While Capone enjoys his reign at the top of the Chicago underworld, Irish gangster Bugs Moran seeks to take him down as revenge for the deaths of his partners Dean O'Banion and Hymie Weiss. On March 7, 1928, Moran orders a hit on one of Capone's top associates, Jack McGurn, the man who took out Hymie Weiss. McGurn survives but Capone decides to retaliate by taking out Moran and as many of his men as possible - all at once. On February 14, 1929, Capone's men dress as law enforcement and raid the liquor buy. They order Moran's men to face the wall for handcuffing, but while their backs are turned, Capone's men shoot all of them. Firing 70 rounds of ammunition in less than 10 seconds, the assassins carry out the biggest gangland hit in American history that will come to be known as the St. Valentine's Day Massacre. Through a stroke of luck, Moran avoids the massacre, but knows he's been defeated.

In 2000, Bill and Hillary Clinton owed millions of dollars in legal debt. Since then, they’ve earned over $130 million. Where did the money come from? Most people assume that the Clintons amassed their wealth through lucrative book deals and high-six figure fees for speaking gigs. Now, Peter Schweizer shows who is really behind those enormous payments. He detailed patterns of official corruption in Washington that led to congressional resignations and new ethics laws. He follows the Clinton money trail, revealing the connection between their personal fortune, their “close personal friends,” the Clinton Foundation, foreign nations, and some of the highest ranks of government.

In the fourth episode of the series, eyewitnesses recall how those in power at Auschwitz lined their pockets with wealth stolen from Jewish inmates while also engaging in illicit affairs.

The human eye can see extraordinary detail, but the eye of a needle held at arm's length is pretty much at the limit of our vision. Anything smaller is simply invisible, at least to the naked eye. But what if we could see this hidden world all around us in greater detail and magnification than ever before? How different would our familiar surroundings then seem? Richard Hammond explores the astonishing miniature universe all around us, revealing that small is not only beautiful, it can also be very, very powerful. From seeing the microscopic changes to ice crystals that can trigger an avalanche to watching in horror the invisible aftermath of a sneeze on a commuter train and learning how the surface of an ordinary-looking plant hides an astounding secret that will make walking on the moon safer, Richard harnesses cutting-edge technologies to transport the viewer into a spectacular micro realm.

Chris Lintott and Maggie Aderin-Pocock report on the reaction to the dramatic announcement of the discovery of phosphine gas in the clouds of Venus, a gas that could be a sign of life. Venus remains an inhospitable and unlikely host. But if not Venus, where in the solar system is the best place to look for alien life? Chris and Maggie investigate the latest missions to Mars and the icy moons of Jupiter and Saturn. Away from the search for life, Pete Lawrencepreviews the best meteor showers of the year.

Mysterious lights shine out from the edge of space, brighter than a trillion suns. They had to be the brightest objects we've ever seen in the universe, putting out amounts of energy that we couldn't possibly explain. So powerful, they can incinerate planets and rip stars to pieces. These are among the most mysterious and most energetic phenomenon in the universe. They can destroy galaxies, but may also be the key to their survival. These objects are a hotbed of all kinds of crazy physics. These celestial powerhouses are called quasars, and we may owe them our very existence.