Drowning in a River of Blood

You are the so-called "Left Hand" of your king. You solve problems that can't be managed inside the bounds of the law. Over the years, you've earned the moniker "the Bloody Left Hand" due to the lengths you're willing to go to in service to your king. He now faces a more pressing threat of invasion from a stronger nation. This time you're not sure if you can stop it single-handedly...