Detective Conan S01 E293 Solitary Island of the Princess and the Dragon King's Palace (The Resolution)

"One truth prevails."

When Conan and Heiji find the name "Kaa" and "Chi" written by Miyako many years ago, they realize who the names are referring to. Conan and Heiji have an epiphany and realize the culprit faked Tiara's time of death.