Part 7 of Prentisspalooza comin’ at ya! Yes, it’s been almost a month since a new episode. No, there’s no compelling argument for why it took this long to come out. The dog days of summer, everyone. Anyway, “Valhalla” kicks the Irish subplot into…gear…as Prentiss archenemy Doyle finally does things besides enter and exit modes of transportation. Is it an improvement? Not really. But Paget Brewster gets to do a lot of ‘worried expression’ acting, and she’s damn competent at that.