Overall it was an excellent and well thought out player event. Some things I think could be improved:
Use an established substitution cipher instead of a random one you just made up.
Have a winning org. I know that my black ops team did secure the hostage and bring her to the council first. I thought this meant we won but apparently there was no winner are "everybody won."
Have a prize. We worked for hours on the event and although it was fun in itself it would be gratifying to get a prize or recognition for winning.