A man is found hanged on a tree, but Sabu deduces that he was killed first than strung up. He also has the distinct odor of opium and the only clue is a talisman from the Prayer Bridge. Lord Tanabe identifies him as one of his men working undercover and charges Sabu with finding the culprit. After waiting for nights near the bridge, Sabu and Ichi see a group of men wearing Tengu masks delivering opium. Sabu breaks one mask, exposing the wearer, so the group attempts to assassinate him at Chief Saheiji's house...