The Norwegian artist Edvard Munch is best known for his expressionist painting The Scream. A pastel version of it fetched $ 120 million when it was last auctioned in 2012, making it the most expensive piece of art ever sold at an auction. The art exhibition Edvard Munch: Trembling, shifts the focus to his landscape paintings, revealing a very different side of the artist and showing the vivid colours he used. Presenting this exhibition on both sides of the Atlantic - in the US, then in Germany and Norway - makes the show open up to a wider audience. But what does it take for an exhibition to go on a journey? The Museum Barberini in Potsdam, Germany grants the BBC exclusive access to witness what happens behind closed doors, when art works worth millions move across countries.