A Time to Screw (2004) +18

Original title: 刻音色

A young man wakes up in an old mansion, isolated among high, snow-topped peaks. The maids tell him that he was carried there after hitting his head, but he doesn't remember a thing. Since he arrived, the old grandfather clock has begun to work again, for the first time since anyone can remember. When the clock strikes twelve, the maids are overcome with irresistible desire, and all manner of orgies and bizarre sex acts fill the mansion.