An experimental program is described to clarify the mechanism of stress corrosion cracking. Elements of film rupture at emergent slip bands, repassivation at rupture sites, anodically enhanced plasticity, brittle crack initiation, and crack growth in micro plane-strain conditions are reviewed, together with plans to determine experimental parameters in a mathematical analog of the mechanism. Variable strain-rate experiments on potentiostated stainless steel electrodes produced anodic current transients that demonstrate the critical effects of competing film rupture and repassivation processes.