Detective Conan Episode 406 -

Yukie is arrested. As she is led away, she looks at Ran and says, "Tell him... tell my husband... I’m sorry we couldn’t keep the promise of the locket." It’s unclear if she means the promise to forget the past or the promise of their marriage.

This episode is an anime-original story (filler) that aired on June 13, 2005. It is a single-episode case featuring Conan, Ran, and Kogoro Mouri. Detective Conan Episode 406

That night, a violent storm cuts the power. When the lights flicker back on, the priceless painting is gone. The glass case protecting it is shattered, and the guard is found unconscious in a room with no windows and only one door—which was locked from the inside with a deadbolt. To make matters worse, the antique silver candleholders from the hallway have also vanished. Yukie is arrested