To a trained wheelwright, everything in the world was a question of rotation, mass, and moving friction. Eren Tal crouched six paces from the shuddering flank of the stone carrier. His boots planted was wide on the greasy cobblestones. His eyes tracked the flight path of the ten-ton cut stone block like a hawk watching a falling timber. The crowd saw an uncontrollable monster. Eren saw a compound swinging weight swinging on a four-point mid-air, with a cycle time of exactly four point two seconds.
His forearm muscles burned as he gripped the fourteen-pound sledgehammer. The air was filled with a high-pitched metal whine—the sound of quartz crystals grinding against each other under forty thousand foot-pounds of clockwork stress. The ground beneath his feet was shaking with a complex ringing tones. Thirty cycles a second from the spirit’s internal holding power, overlaid by the four-second surge of its forced delivery stroke.
‘The left heel-stone is lifting three inches on the recoil,’ Eren called out to Pella over the roar. ‘When it rocks back to gather driving force, the weight transfers entirely to the front fore-limbs for half a second. That’s our window. If we shove twelve inches of seasoned oak under that heel-stone while it’s in the air, the beast won’t be able to rock forward onto its toes. It will bottom out on the timber sole-plate.’
