The characters are walking along a beach (or any place filled with sand will do) when a lightning bolt strikes the ground a couple feet in front of them. This works really well when the PCs are fearing divine retribution. The heat from the bolt is hot enough to melt the sand into glass. When the PCs investigate, they find 1d4 pieces of glass that deal 1d12 damage on unarmored opponents and 1d6 on armored ones. Each piece will break on a miss, on a critical miss, and on a critical hit due to the glass hitting metal (armor on a miss), or hitting bone beneath flesh.