Bitcoin is the world's leading virtual currency, but unlike real money, it is not backed by a government or properly regulated. Bitcoin is exchanged and held digitally by users - which is attractive to criminals selling drugs, pornography and arms. But now Bitcoin is moving into the mainstream and being openly marketed as an investment opportunity. The film investigates what Bitcoin is and what it means, going inside a Bitcoin mine in Iceland - where currency is made - and spending time with the Bitcoin millionaires of Silicon Valley.
The programme also hears from others who have been scammed out of their life savings and investors who think the cryptocurrency is an enormous scam and that the writing is on the wall. Around the world, authorities are sounding the alarm that Bitcoin is too risky - is it too late, or too crazy, to try to become a Bitcoin millionaire?

April 1453. Sultan Mehmed II unleashes an artillery attack on Constantinople unlike any the world has ever known. It's the largest concentration of cannons that the world had seen in one place. The monumental task of keeping the Ottomans out of Constantinople falls on the shoulders of Genoese soldier of fortune Giovanni Giustiniani. He and his men must defend 14 miles of city walls. Mehmed launches his ambitious plans to break through the walls of Constantinople, but Giustiniani's mercenaries manage to forestall the attacks.

Three years after the devastating fire, Lucy Worsley has exclusive access to the Cathedral of Notre-Dame de Paris at a key turning point of the restoration. Work to rebuild and restore the monument is being ramped up in a bid to meet the ambitious deadline to reopen it to the public in 2024. Scaffolding now fills the interior of the cathedral, giving Lucy and the team unprecedented close-up access to every inch of the structure. Lucy meets scientists, historians and craftspeople working to return the 850-year-old Gothic masterpiece to its former glory.
The fire coated Notre-Dame with tons of toxic lead dust, so specialists are now decontaminating the site. Unique access to the stunning rose windows allows Lucy and the stained-glass historians to uncover the mysteries of these enigmatic 13th-century works of art. An unforeseen legacy of the fire threatens to destroy the remaining vaulting, so the team must develop an ingenious solution to save the stonework. The loss of the roof during the fire reveals hundreds of large iron staples embedded in the stone along the top of the walls. And the incredible task of sourcing and cutting two-thousand perfect oaks gets underway to rebuild the world's most complex medieval timber structure - Notre-Dame's extraordinary roof and spire.

Schwalmstadt Maximum Security Prison in Germany. Locked up behind the walls of this 12th-century castle are 188 of Germany's worst offenders. The prison is a fortress surrounded by a moat, and houses dangerous criminals, many of whom attend intense therapy sessions.

Jennifer Griffith and Sarah Carver were working for the Disability Administration and noticed all this corruption firsthand. They wrote to the Social Security Administration, wrote to lawyers, wrote to the president of the United States. But nothing ever came of their complaints until the Wall Street Journal story broke. Then, with national attention brought to Conn, the Senate, the FBI and the SSA (who’d been enabling the fraud the whole time) finally stepped in.
Series finale. Eric leads the government on a wild goose chase. The fallout from the fraud takes its toll on a struggling Kentucky community.

Vlad Dracula presses an increasingly desperate guerrilla campaign from the shadows, hoping to demoralize the Ottomans and slow their march north. After chasing Vlad for two weeks, sultan Mehmed II and his invading army find themselves caught in a nightmare come to life deep within the Wallachian forest. Many legends have arisen out of the invasion of Wallachia in 1462. One speaks of Vlad Dracula launching a biological attack against the Ottomans to slow their march to his capital city, Târgovişte. Vlad opened his prisons and released hardened criminals to go amongst the Ottomans with tuberculosis and bubonic plague so that they could infect the enemies.
Vlad Dracula also had carried out a scorched-earth policy against Mehmed II. Along with his hit-and-run campaign from the shadows has left the sultan's troops on edge. As Mehmed's army closes on Târgovişte, tensions flare in the Ottoman camp, where food and water are in increasingly short supply. But Vlad had nowhere to rely on food for himself either and there was nowhere to go anymore. He became a prisoner of his own scorched-earth policy. Radu Dracula closes in to take Princess Anastasia hostage. Anastasia commits suicide when he reach her at Poenari castle.