You decide to try some tactics which might actually be useful. You place restrictions which hinder local commerce, but ultimately work to slow the spread of the disease both into the town and out from it. This doesn't eliminate the plague, of course, but your methods give this area a higher survival rate than anywhere around. When you finally decide you're done and report back to the capitol...well, you did a great job, but all they see is the desolation of the plague. Without a single kind word for your duty, you're executed alongside a dozen other people tasked with eliminating the disease.