"Freshman" ends in disaster and the Germans realize that the plant in Rjukan was the target of the operation. Security measures are tightened and the Americans see only one way out: bomb the plant. However, Tronstad makes it clear to them that the building is too solidly built. A small special unit is to infiltrate the complex and deliberately blow up the facilities in the basement. Immediately, the preparations for operation "Gunnerside" begin...