If “The Hobbit: An Unexpected Journey” was a single-serving tribute to the fans of the J.R.R. Tolkien book that inspired it, its follow up, “The Desolation of Smaug,” offers a nod to the uninitiated moviegoing audiences that made a prequel trilogy possible.
Eschewing the kitchen-sink 
minutiae of the first installment (or maybe just having used all of it up) Peter Jackson creates a rousing, immersive sequel that offers the same sort of sweeping action — and more crucially, emotional engagement — that helped the “Rings” films become a cultural phenomenon, regardless whether or not you were familiar with the source material.