Four movies opened in wide release last Friday, but only three, City of Ember, Body of Lies, and The Express, were screened for critics beforehand. The fourth, Quarantine, was kept hidden away, which has become common practice with the studios and their horror films. I like to call those movies Hollywood's Shameful Secrets.

Funny thing, though. According to Rotten Tomatoes, the critics who eventually saw Quarantine liked it better than most of the stuff the studios weren't ashamed to show. At the moment, it has a 61% Fresh ranking. The Express is only slightly higher, at 64%, while Body of Lies is far below it at 52%, and City of Ember is way back at 46%. At Metacritic, which comes up with an average score between 1 and 100 for each film, all four movies are basically tied: 54 for Quarantine and 58 for the other three.

So what gives here? About 95 percent of the time, if a movie isn't screened before it opens, it's mediocre at best, and it's usually downright bad. If Quarantine is actually pretty good -- better than the other new films last week, anyway -- why didn't Screen Gems let critics see it?