~gasp!~ ~shock!~ ~horror!~
Anyway...
You really can feel the axe man commith. I mean sure there should always be ways around a cities security, and festivals are prime targets for terrorism. But a place hosting a gathering for the royalty of 5 nations? Yeah, your are either lacking in imagination or are seriously underestimating how much easier it would have been to decapitate the leadership then the widespread chaos of a fortified castle city.