The episode opens with the Mori Agency receiving a peculiar request. A man named Takaaki Tooyama (the father of Heiji's rival, Kazuha) asks Kogoro to hide a fugitive—a man named Toru Amuro. Yes, that Toru Amuro.

A: Yes. Episode 671 ends on a cliffhanger. The mystery is only fully resolved in Episode 672.

The episode takes place almost entirely inside the Poirot Cafe and a luxury hotel suite. The atmosphere is thick with paranoia. Every glance Conan gives Amuro feels like a chess move.

In an era where Detective Conan episodes can sometimes feel repetitive, Episode 671 stands as a reminder of the series’ enduring charm. It’s a tightly written, atmospheric mystery that respects its audience’s intelligence. The "Masked Ball" is not just a party—it’s a puzzle box waiting to be cracked, and watching Conan turn the key is as satisfying today as it was in 2012.

The episode opens with the Mori family receiving an unusual invitation. The late art collector, Tajima Hyosuke, has organized a posthumous "Masked Ball" at his lavish Venetian-style mansion. The catch? To attend, every guest must wear a full-face mask, hiding their identity completely. Kogoro is intrigued by the promise of expensive wine and fine dining, while Ran is drawn to the romance of the masquerade. Conan, ever suspicious, tags along.

Using his infamous deduction skills (and the voice-changing bowtie to mimic Kogoro), Conan reveals that the cipher is a Caesar cipher shifting letters backward by three positions.

Some critics note that the resolution relies on a coincidence—the victim happening to have a penchant for classical ciphers. But in the world of Conan , where victims often leave elaborate dying messages, this suspension of disbelief is easily earned.