Vienna of 1840 faces a deadly mystery. Pregnant women are entering its Clinic Number 1 and never leaving, killed in high numbers by deathbed fever. When a prickly doctor doggedly uncovers the reason, he is punished for his theory. And young mothers keep dying. The cautionary tale of Dr. Ignaz Semmelweis.

A poor girl trapped in an abusive marriage, a world-famous entertainer taking Europe by storm, a decorated hero of Nazi resistance, an American civil rights icon – all the same woman. This episode tells the story of the remarkable life of Josephine Baker.

A shadowy figure runs a massive Nazi spy network from the heart of London under the noses of the British during WWII. The catch? The network is a fiction, the work of a self-made spy trying to help the Allies, whether they want him or not. The amazing story of Juan Pujols Garcia.

Fate conspires to destroy an 18th century love story by separating the couple with a nearly impassable gulf. Only an epic historical expedition can reunite them – if they survive. The remarkable tale of Isabel and Jean Godin Des Odainis.

In 1983, one of the greatest underdog stories in modern history unfolded in Australia over the course of five days when a 61-year-old sheep farmer ran a seemingly impossible race. This episode tells the improbable story of Cliff Young.

An all-American girl trapped inside adversarial Japan when WWII erupts, she not only survives but manages to aid her imprisoned countrymen while subtly undermining the enemy. Her reward? A charge of treason levied by her own nation. This episode tells the winding tale of Iva Toguri D’Aquino.

Everyone knows that Ferdinand Magellan was the first person to circle the Earth. Wasn't he? The answer is both simple and surprisingly complex and features a fascinating cast of characters and plot twists galore. This episode tells the story of the epic 16th-century voyage that changed the course of world history.

What if a single person could save the world from apocalypse? For five thousand years, humans have predicted the end of the world with helpless anticipation of destructive forces beyond our control. However, three times an obscure individual averted nuclear annihilation on our behalf. This episode tells the story of those unsung heroes.