The ".5" designation is crucial. It signals to automated TV guide systems and streaming algorithms that this episode is not sequential canon (it doesn't advance the plot beyond 1077), but it is essential for understanding 1078 and the movie.
He blows out the match.
In the official Detective Conan (Case Closed) anime canon, there is no episode numbered "1077.5." The numbering system does not use decimals. Detective Conan Episode 1077.5
While there is no official in the Detective Conan (Case Closed) anime, we can imagine this "lost chapter" as a bridge between the Black Organization suspense and a classic "locked-room" logic puzzle. The Setup: The Whispering Gallery In the official Detective Conan (Case Closed) anime
, here is a deep guide to the episode. If you meant a different episode (like a special OVA), please clarify, but this guide covers the canonical Episode 1077. If you meant a different episode (like a
: In the Black Organization episodes following 1077, Conan and the FBI investigate a coded piece of paper (or "piece" of evidence) found on a fallen FBI agent. Conan cracks the code by printing two copies and reversing one, a key "piece" of the puzzle that allows them to lure the Organization into a trap.