Detective Conan S01 E670 Treasure in the Tower of Darkness (2)

"One truth prevails."

While investigating in a tunnel, Conan is separated from everybody else. As he realizes he has ventured into the tower itself, he lets everybody into the tower. He then tranquilizes Kogoro and explains that Momoe's death was an accident due holography and a misunderstanding. Afterwards, Haibara, Ayumi, Mitsuhiko, and Genta are discovered to be safe and that the treasure hidden in the tower was a giant kaleidoscope.