Okino Yoko and the Locked Attic (1)

Okino Yoko comes to the Mori Detective Agency to ask him to solve a murder that happened at a villa. Several days earlier, Yoko headed to a villa where a Nichiuri TV producer's sister went missing after she got married to scout the location. His sister's husband and brother- and sister-in-law were there as well. But the night they decided to stay at the villa... Just as he was preparing to explain his deduction, Kogoro shuts himself inside the bathroom instead. Wakita Kanenori from Iroha Sushi shows up at the office, and then--?!