After a slightly slow start (which eventually paid off), the fourth season of “Girls” quickly turned into the most consistent and mature run of episodes that the show’s put together, and perhaps the best since the stellar debut season. The opening episode felt more like an epilogue to the previous finale, and taking Lena Dunham’s Hannah out of Brooklyn and placing her in the Iowa Writing Workshop never gelled, but the show quickly revealed that that was the point: Hannah might have the talent to be a professional writer, but she doesn’t have the temperament, and the character soon made the surprisingly self-aware decision to give up on her long-held dream and become a teacher. Putting her life in disarray signaled Dunham and co-showrunner Jenni Konner’s refusal to let the show carry along in its groove, and four seasons in, they also proved better at juggling their ensemble. Every existing character got meaty storylines (even Shoshanna, who’d been consistently underserved), and some strong new ones were introduced, most notably the terrific Gillian Jacobs as Mimi-Rose, Adam’s new girlfriend (points also for creating, in Ebon Moss-Bachrach’s Desi, a character more loathsome than any incestuous child-murderer in “Game Of Thrones”). The shock of the new is long gone with “Girls,” and this show may not have episodes that reached the highs of say, the Patrick Wilson season two installment, but it’s grown and improved to a hugely impressive degree, and still remains appointment viewing.