Trainwreck is a strong word. Average is another strong word. Mediocre sounds about right. Serena isn't necessarily a film that Bradley Cooper and Jennifer Lawrence should concern themselves with burying, it'll be forgotten at the bottom of the bargain bin in no time, but it's not something to be proud of either. Director Susanne Bier, whose 2010 film In A Better World won the Foreign Language Oscar, just doesn't seem to know what to do with the material and it's…
