Sorry to say I figure it out right away. I am not sure was this suppose to be funny? Perhaps if you made it to where the Knights tried more complicated and indepth methods to begin with I might have found it more intresting. The answer to thier problem was obvious to me from the start. It can be dificult wuth a plot like this but the goal should be to make the answer obvious but to distract the reader from it. What you want is to have the reader say to them selves in the end is this.
"Why didn't I figure that out!" To write something like that takes more effort then you may realize. To the authors credit I did finish the story so it held my attention to the end.