神龙见首不见尾

Explanation: About poetry was originally a charm, after the analogy of people's whereabouts hidden, just one showed up and disappeared. Also be used to flash words, make unpredictable. 　　Usage: Complex sentence; as object clause; containing derogatory 　　Source: Qing Zhao Zhixin, "On the Long recorded": "poetry, such as dragon, saw the first but not the tail, or a cloud in the dew claws of a scale only, Andhra all?" Thesaurus:  Play cat and mouse