After the border had officially been closed, the students were separated and often didn't know if their friends on the other side were OK. Luckily, a few letters got through.

In a collage of historical reenactment and original interviews, this film looks at the assassination attempts made on Hitler towards the end of World War II.

The restrictions placed on residents of both West and East Berlin intensifies to the point where the classmates aren't even actually allowed to have contact.

Fitness applications are some of the most successful examples of gamification at the moment. However, many scientists and corporations see a lot of potential for motivating people in the workplace as well.

Rüdiger and Bärbel attempt to escape into West Berlin, but it doesn't go according to plan.

After another failed attempt, Gersdorff and his co-conspirators contact other officers to assist them with the assassination of Hitler.

Do you know what quantum physics involves? The thought experiment of Schrödinger's cat is a good way to understand the basic premise.

Gersdorff attempts to convince various high-ranking officials to join their plan, but not everyone believes that a coup would be the best solution for Germany.

While their classmates in the West graduate, Rüdiger and Christian come to terms with their life in the East Berlin.

This video uses virtual reality technology to allow viewers to experience the power of a volcano close-up.

Germany is under attack and time is of the essence, but it is difficult to find co-conspirators. When Claus Schenk Graf von Stauffenberg returns to Berlin, it seems possible that they have found a potential source of help.

Rüdiger finds himself in prison, subject to interrogation, and separated from his sister.

What must come after the assassination? Stauffenberg and Gersdorff discuss their strategies and their doubts.

While Rüdiger and Bärbel face the consequences of their actions, the other former classmates move on in more positive ways.

Claus Schenk Graf von Stauffenberg recruits Axel von dem Bussche, a young captain haunted by Nazi atrocities he has witnessed, as Hitler's so-called "European Fortress" begins to crumble.