Bone-Chiller!

Thirteen people gather on Friday the 13th at the Travers mansion in New York for the reading of Josiah's will which is a wall chart rendered in the form of a rebus (a part word, part drawing puzzle) that almost defies solution. Instead of designating an heir, it offers the estate to anyone who can solve the will! The lights keep going out and people keep getting murdered. The audience will have a ball trying to untangle the puzzle faster than the hapless characters. By the final act, revelations are exploding as surprise piles upon surprise and gasps alternate with howls of laughter.