Ep. 572: Conan reveals the warehouse's hidden secret room using an abacus switch to catch a serial robber.

572

Conan determines that Samizu Kichiemon designed the warehouse and that an abacus serves as the mechanism to reveal a secret room. The Detective Boys and Conan have the owner contact the police before presenting their deductions. Upon arrival, the police learn that the low ceiling was disguised by the interior design, with a fake window installed to mimic the distance between the exterior window and ceiling. Conan explains that arranging the abacus to display the Kanji for Samizu lowers the ceiling, exposing the hidden space where they find a man. This individual is identified as a serial robber possessing stolen goods. Conan then reveals to the Detective Boys that Heiji has been providing advice from hiding and forces him to emerge.