A young couple's elopement takes a dark turn when their car breaks down near the Green Dragon, an inn shrouded in eerie silence. Warned by a drunken tramp that the dragon on the sign changes its eye from yellow to red, and that no one answers the door, they press on-only to find the door now open. Inside, a half-prepared tea, a dropped bread knife, and a fresh bloodstain hint at recent violence. As a menacing Chinaman seeks a missing dog and a blind man's whereabouts remain unknown, the couple must untangle the inn's secrets before they become its next victims.
Their honeymoon becomes a fight for survival as they encounter a blind man and his dog, a mysterious artist, and a silent Oriental intruder. The old inn, once a place of romance, now holds a dark terror. With no help in sight, they must rely on a tramp named Alf and their own wits to uncover what the Green Dragon hides.