Shen Qian, a fresh graduate, rents a haunted house to save money, encountering bizarre events such as ghosts knocking on her door at midnight and learning that three girls previously went missing inside the room. She wants to cancel the lease, but the shady real estate agent demands a 100,000-yuan penalty fee, leaving her with no choice but to give up due to her inability to pay. At this moment, the security guard Wang Anquan proactively helps her and reveals that the old woman across the hall who always glared fiercely at her has long passed away. Driven to a dead end, Shen Qian trusts him, and after disclosing her hiding spot, she ends up being human-trafficked. Just as the shady agent and Wang Anquan are making the transaction, the inspectors rush in to rescue all the hostages and capture the gang. It turns out that Shen Qian is an undercover agent, and all of this is a plan to flush out the snake from its hole.