Complex sentence: Doom, thus saving the day with Frodo's hand still intact, the same effect would have occured, but the reader would be wondering from where this new character (to whom the author had never once referred) came.
Split into simpler sentences: Doom, thus saving the day with Frodo's hand still intact. The same effect would have occured, but the reader would be left to wonder from where this new character (to whom the author had never once referred) came.