Third Graders Miles, Ellen and Kendra discover more than the answer to the mystery of the missing arrowhead in this fictional tale. The Lighthouse Mystery was written to commemorate the installation of an 1877 replica Fresnal lens for the Vermilion Ohio lighthouse. The lighting of this lens means that the lighthouse, an exact copy of the one made in 1877 from melted obsolete cannons, is now a U.S. Coast Guard sanctioned private navigational aid and is included in navigational charts.