He was a lawyer and business man. He became anti Nazi and planned to assassinate Hitler as during the knight of Long knives many of the opponents of Hitler were murdered. He befriended Josef Roemer and he agreed to kill hitler either by shooting or a grenade, However it did not materialise. Roemer was arrested and toured severely by the Gestapo and he revealed the names and Nicolaus was arrested on 26 February 1942 and tried and sentenced to death for treason and for anti govt activities. He was executed at Brandenberg prison in a Guillotine.