1) Comic by John Wagner 
==Premise== Harry Exton, a mercenary, is a `Button Man`, a hired killer pitted against other killers in an underground sport. Each works for a mysterious `Voice`, a rich man of unknown identity. The object of the game is to kill one`s opponent, or capture him and take his marker – the first two joints of a finger. Button Men who lose three ...
The control switch of a conveyor belt, which was operated by the button-man, who was usually an old ex-collier or someone not fit enough for heavy manual work because of ill health or injury.
soldier (def. 5).