The blow caught him in the small the back, hurling him forward, face-first, into the opening. It was the cudgel, held firmly at shoulder level, that saved him from serious injury, perhaps worse-breaking impact of this fall by catching against the side of the opening and becoming jammed there, in the gap where a break had crumbled away, long enough to cause him to swing slideways then backboards, so that instead of hurling down head-first he struck the steps first with his hip, then his shoulder, to go sliding down on his back, bumping from step to step, stunned rather than injured by the first impact, unconscious even before he reached the ground.
Used availability for L P Davies's What Did I Do Tomorrow?
September 1973 : UK Hardback
1972 : USA Hardback
March 2008 : UK Paperback