Immediately following the "A Knife In The Dark" level, you will need to forge a path for the hobbits in the stage named "Trollshaws." Instead of moving ahead yourself, however, let the four hobbits go in front. They will actually kill the enemies faster and better than you yourself can, and they will not pick up the Crams and Lembas. In short, let the four companions do the dirty work, firing a few arrows to cover then and there, then rake up the health goodies afterwards.