The third inconsistency came only after Ethan decided to verify the story himself.
According to all three of them, both Nathan and Irene had been buried.
So, Ethan had their graves opened to find that there were no skeletons inside.
Of course, Ethan wasn't foolish enough to immediately treat that as absolute proof.
This could also have meant, that a summoner who knew who Nathan and Irene were could have discovered the graves years later, excavated the bodies, and took their dead parts as catalysts.
That alone prevented the empty graves from becoming decisive evidence. But, neither did they invalidate the first two inconsistencies.
—
After piecing everything together, Ethan eventually arrived at a conclusion.
The problem wasn't merely that the story surrounding his parents' deaths had been falsified.
Someone had tampered with their memories.
