He can be found in Highmoon Hall, the residence of Morthal's ruler, Jarl Idgrod Ravencrone, unless the Dragonborn chooses to take Hjaalmarch for the Stormcloaks, after which he is found in the Hjaalmarch Imperial Camp.
Taurinus is the Legate that the forged version of the Imperial Documents must be given to in this quest.
This quest can be initiated by speaking with Taurinus and selecting the dialogue option, Is there a story behind that burned down house? He will respond with the same dialogue as the guards use when asked.
A False FrontEdit
"Thank you soldier. Let's take a look at these reports..."
"Is that so? Lost your uniform along the way did you, soldier?"
- Ditched it for this. Easier to sneak past the guard. "I suppose it would be. Good thinking. Thank you soldier. Let's take a look at these reports..."
"I'm waiting on word about reinforcements for the fort... Good, they're on the way. And we have some information on enemy troop movements. Excellent. Stormcloaks are making it difficult to move around. It's good you made it here in one piece. Why don't you have yourself a drink at the Moorside before you head back?"