Lou Ye’s beguiling movie tells the hazy, cut-up tale of a motorcycle courier once hired to follow a woman he then fell for, who subsequently threw herself into the river but seems to have been reborn as a nightclub performer dressed as a mermaid. With its drifting, subjective camera capturing jump-cut collages of street life in the neon-splashed city, it’s a fascinatingly intimate portrait of the Shanghai river front, wrapped around a mystery.