In Nazi Germany, in 1941, there was a factory in the north German town of Seelze. Though officially its function was a top military secret, it was known to be associated with the manufacture of poison gases. Until a raid put the factory out of action ... Based on fact, this is the story of five men who were parachuted in to Seelze to destroy the chemical plant. But the Gestapo were waiting -- and one of the five was a traitor ...