Two trips to the Balkans, in South-Eastern Europe might hold the key to the terrorist's mindset in the years before the attack. This is a region steeped in nationalist history and revered by the far-right, and the details of his time here are murky. 

Joey follows the terrorist to the other side of the world, searching for more clues about his radicalisation, trying to find out if anyone in Europe knew what was coming. 

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