First let’s discuss what is Deus ex Machina, this is when the author puts a magical solution to a problem face by one of the characters in front of the character without explanation. One example of this is seen in Beowulf, when Beowulf is fight Grendel’s mother who is a giant swamp monster. During the battle Beowulf realizes that his sword can’t pierce the monster to kill it, and when he looks over to the cavern wall he sees a giant bejeweled sword that has the magic power of being able to kill said monster. Now I don’t know about you, but if I was a villain and knew there was only one thing that could stop my evil plan I would destroy it, not hang it on my wall. Here is the problem with Deus ex Machina, it is just an underdeveloped plot point. One series I love is Harry Potter, and one of the things I love about this series is that even when you think something is a Deus ex Machina it isn’t. You are purposely left in the dark about what really happen until it makes the most sense to revel it, and then everything is explained. In my opinion just leaving a very important plot point unexplained is just not enough thought into what is being written, but again that is just my opinion.