When they fell into a sleep late at night, suddenly a few men (probably they were Toshizo HIJIKATA, Keisuke YAMANAMI, Soji OKITA, Sanosuke HARADA from Shieikanha group) stepped in the bed room at the back; they killed SERIZAWA and HIRAYAMA, as well as Oume who was present at that moment.
芹沢たちが寝入った深夜、突然、数人の男たち（試衛館派の土方歳三、山南敬助、沖田総司、原田左之助という説が有力）が奥の部屋へ踏み込み、芹沢と平山を殺害し、その場にいたお梅を惨殺して立ち去った。