Heligoland, April 18, 1947: Preparations for one of the largest non-nuclear explosions in history are almost complete. The British want to raze the island to the ground with more than 6,000 tons of explosives - nothing should remind of the sea fortress with its air raid shelters and anti-aircraft systems, with the submarine bunker and naval port. The Heligolanders have been evacuated and are waiting with bated breath for the outcome of the “Big Bang” in Hamburg and Cuxhaven, on Sylt, in Schleswig and Wilhelmshaven. Will they ever be able to set foot on the red rock again - or will the island's history come to an end in an explosion that historians will later measure as the size of atomic bombs?