gallows; the thirteen steps
Euphemistic or indirect reference to the gallows, based on the traditional number of steps leading up to the execution platform. Often used in literary or historical contexts.
See also: 絞首台 (こうしゅだい)
He was destined to climb the thirteen steps.
In that novel, the thirteen steps are depicted as a symbol of the gallows.
絞首台 is the direct term for 'gallows', while 十三階段 is a euphemistic or symbolic expression referring to the same thing.
Literally 'thirteen steps', referring to the traditional number of steps leading to the gallows platform. The term is used euphemistically for the gallows itself.