I unexpectedly received an email from my late sister, directing me to an abandoned bar on the top floor of No. 18 on the Bund. The moment the elevator doors opened, the stench of blood hit me. On the wall, someone had written "Welcome home, little sister" in blood. When I turned around, I saw my sister, who had died by suicide seven years ago, smiling behind me, holding a human-skin mask that fit my face perfectly.