“Masterpiece” is a term too many critics use with too little discernment, but I feel comfortable applying it to Jonathan Glazer's extraordinary sci-fi vision “Under the Skin,” which has drawn strong opinions in every direction since premiering at Telluride and Venice last year. Reviews were initially shaky, but as was the case with Glazer's last film, “Birth,” nine years ago, it didn't take long for an ardent army of critical defenders to form. The less you know about going in, the better — but I will say that it proves Glazer to be among the greatest sensualists working in cinema today, and Scarlett Johansson as a movie star of uncommon magnetism and daring. Go see what you think, and report back below; either way, it's not a film any serious film lover can afford to skip.