Skyrim:Guild Mage's Note

Skyrim: Items: Notes: Books
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Added by Dawnfang & Duskfang
ID FExxx81D
SeeĀ Also Lore version
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Guild Mage's Note
A mage's theory on Dawnfang/Dawnfang's magic canceling capabilities

How could this have happened? Our plans should have worked. But who could foresee that his weapon would interfere with our simple enchantments. And now we have become ensnared in our own trap.

What is this weapon and what does it herald?