Detective Conan S01 E716 Dancing Demon in the Noh Mask Mansion (1)

"One truth prevails."

Detective Mouri, Ran and Conan shows up at a museum explaining that they received a letter warning them that the museum curator's life is in danger. They meet the museum curator, his personal nurse, and his businessman acquaintance in the garden. Soon a heavy pile of logs roll out of the shed and almost crush the group. Other "accidents" occur until the businessman is poisoned and dies.