Every once and a while, Gadfly sticks in a VHS (we’re old fashioned) and relaxes with a cold cup of flower nectar; then he shares his thoughts with you. Remember our review last summer of “The Cartel,” that exposé of the New Jersey education system? Well, if you’re a beltway insider (or just-outsider), you’re in luck, because it’s showing, for free, as part of the D.C. Independent Film Festival at noon on Sunday March 7. Despite being gratis, you have to reserve tickets in advance, so find more information here.