Stuck on Quest, Need help

[Origin1]

I am stuck in chapter 35: Divine Madness. 

 

After killing 10 soulless soldiers, I am stuck at "read yu chun's letter". I don't have that letter in my inventory or mailbox. Farming soulless soldiers seems fruitless in getting me the letter. What should I do?

 

PS. IS BnS screenshot designed to be captive of only a portion of the screen?

[Zazzy]

The letter is in your quest log not inventory