Hazure Skill: The Guild Member with a Worthless Skill Is Actually a Legendary Assassin, Vol. 5 (light novel)

Someone is plotting to take over the Felind Kingdom, and they've hired an assassin to kill Princess Almelia. Naturally, Roland is tasked with protecting the girl; who better to protect her from an assassin than another one, right? However, Roland's foe is no ordinary killer this time. It's the very woman who taught him all he knows. Can the legendary assassin kill his master? Does he even want to?