Orwald is involved in the quest Offered and Lost.
Hawke encounters Orwald celebrating with a few friends at The Hanged Man while off duty. Hawke then approaches him, which will lead to a fight; after defeating him, Orwald reveals that he was under orders by a templar bearing the seal of the grand cleric.
If Varric is not in the current party, he will come down from his hidey hole and help fight.
Alternatively, if Aveline is present and the option for her to step in is used, no fight breaks out and Orwald will confess before being sent for punishment on Aveline's orders.