do you know much about the history of the search for the cup, or the davinci code?
(i think i saw ken holding the one that he thinks is the holy grail
you could make different houses the various countries that was supposed to have hidden the chalice, like ethiopia, france, italy, israel, egypt, england, etc.
then when they can't find it, you could spring the mary magdelene/davinci's "last supper" dealio on them.
i think giving clues to find different countries would be the way to go. you could even have the neighbors dress as people from that country, especially the middle eastern countries. they could try to repel the little infidels...
of course, the cup resides in new jersey, near the vince lombardi rest area on the turnpike. shhhhhhhhhh!