Saved by the gun

Sean is a soldier seeking for an object that some consider a myth : the weapon of miracles! Here's the problem : the more he seeks it, the more he gets in trouble... especially when he metts an elf princess in chains, and a huge bear, being mistaken for the weapon of miracles. But what does the weapon of miracles look like ? Where does it come from ? Why do sean need it ? How far is he willing to go to get it ? Not to mention that he always have his 10 years old daughter with him in the battlefield ...