Hazure Skill: The Guild Member with a Worthless Skill Is Actually a Legendary Assassin, Vol. 4 (light novel)

Roland is the Adventurers Guild's ace in both name and deed, and a formerlegendary
assassin. For his next quest, he is sent to help rebuild theHadenberg Kingdom, which
has been torn apart by war with the demon lord'sarmy. There's far more waiting for
him than a normal guild assignment,however. Someone is scheming to kidnap a queen
that Roland just happens tohave met before...