My first thought with this episode was: "RILEY YAY!" then "don't put Riley in a corner!
"
From what I understand, her behavior started to get in her way. Last time we saw Riley she was bitter and drunk, that never build a shiny soldier (specially one who never had a military background). So my guess is that she's a crappy soldier mostly because of her new and VENGEANCE NOW personality. And second, maybe she's not doing so well without a bow. It's a shame, really, because she's such a badass with what she knows and everyone else who never saw the Legolas Action Scenes seem to look down on her.
Bookmarks