Talk:Missions/@comment-212.60.30.92-20110310094142/@comment-3069692-20110310154455

The bosses in Bangkok have always been just a click>done scenerio... not like the Las Vegas and Italy bosses. So my guess is that you just have to click it to complete the mastery (it is the final boss/job in the Assassin tier). The FAQ for Battle In Bangkok also states that if you have already mastered Bangkok then this task will be automatically checked off for you, supporting the theory). I'm sure somebody will confirm sooner or later though.