Who is Johnny Cook from Flashman & the Angel of the Lord: From the Flashman Papers, 1858-59 and what is their importance? "Flashman_&_the_Angel_of_the_Lord:_From_the_Flashman_Papers

A historical character, Cook is John Brown's man inside Harper's Ferry for a year before the raid. He works as a teacher and frets about whether the slaves should rise up and join Brown and, if so, how will they know to rise up? Used to having his ideas rejected, Cook is happy when Brown is enthusiastic about taking hostage Col. Washington, a distant descendant of the first President.