The real surprise isn’t that primes have patterns. it’s that once two primes sit a fixed distance (h) apart, the next prime is no longer free. Its possible locations are finite. Arithmetic closes the door. A new parameter free law now predicts the “lockstep” correlation the chance that the immediate next prime also has a partner at the same distance using only Hardy–Littlewood densities and inclusion-exclusion. No gap histograms. No fitted constants. It was locked before the data. One case predicted exact zero. The computer found zero. Nine other blind shifts averaged 0.44% error. As X grows the entire problem collapses to a single three-term progression. When 3 doesn’t divide h, the lockstep rate is forced to vanish. The primes look random until you condition on consecutive structure. Then the modular walls appear. The animation is the visual version of that process prime points entering the funnel, forbidden branches disappearing, allowed correlations surviving, and the many possible gaps collapsing toward the final arithmetic structure. The Lockstep Law A Parameter-Free Hardy–Littlewood Predictor for Consecutive Prime Correlations The Prime Lattice Coherence Framework: A Unified Master Document