STILLRELAY: Every Step Calls the Next Light.

STILLRELAY is a self-authored Red Light/Green Light queue puzzle. The mechanical owl publishes two calls. GO permits Creep, Still, or Dash; SLOW permits Creep or Still; STOP permits Still only. Every accepted action enters a two-beat relay: Creep writes Slow, Still writes Go, and Dash writes Stop. What the runner does now becomes the law two beats later.