The Tumbler Sequence

I slipped into the courtyard through the base gap of the ground-floor exit door. A commuter bicycle stood propped against the weathered brick wall, offering an immediate ascent route. I scaled the kickstand and balanced along the lower chainstay. Suspended between the rear wheel spokes hung a heavy four-dial combination lock. Bracing my boots against the painted frame, I gripped the second tumbler with both hands. The notched dial yielded with a sharp, dry mechanical click, locking the numeral into alignment. The internal spring tension is stiff with zero lateral slack. I logged the resistance before descending back to the stone pavers.