Plot
A year after the events of the previous film, federal police detective Aaron Falk attempts to coerce further information about a money laundering scheme from a company employee, Alice Russell, but she refuses to give him any further information.
The following day, she embarks on a corporate hiking retreat with four other employees, her boss Jill Bailey, childhood friend Lauren, and sisters Brianna and Bethany. Three days later, Falk receives an incomprehensible call from Alice which quickly drops out, only to be later informed by fellow agent Carmen Cooper that Alice’s hiking partners had returned from their trip injured, and Alice is missing. Suspecting something has happened to her due to her being a whistle blower, Falk and Cooper quickly join the search to find her.
In flashbacks, it is revealed that Falk’s mother also disappeared from the same area during a hiking trip with him and his father. After tirelessly searching for her for days, the pair finally found her injured and malnourished, but she ultimately died shortly after.
Alice's hiking partners reveal that during the first night of the trip, Jill's husband, Daniel, who was responsible for the laundering scheme, met up with the group, and led Alice away from them. Afterwards, Alice became frantic and desperate to leave the trip early, even after Daniel leaves. Brianna, who has been hospitalised due to a bite from a funnel web spider, reveals that she'd misread the map in her hungover state, and caused the group to become lost. While attempting to follow the river back home, the map falls into the water, and Lauren is injured while attempting to retrieve it. Bethany later admits to Falk that she previously had a drug problem, which had resulted in her serving jail time due to her neighbours reporting her for selling her sister’s belongings for drug money. This caused Alice to lose trust in her.
As the group continues on, Jill discovers that Alice has seemingly been intentionally leading the group in the wrong direction and becomes furious. The following day, the group discovers an abandoned cabin, and decide to stay there for the night despite Alice’s protests. Later on, they discover the gravesite of a dog, causing Alice to insist they may be on the hunting grounds of an infamous serial killer who lured his victims using his dog, but the group brushes her fear off as her trying to persuade them to leave the cabin. Using a detail about bats from the group’s recounting of events, Falk is able to locate the cabin, where he finds the body of Alice nearby, and discovers a disturbed funnel web spider web near her body, hinting at Brianna being the culprit. Upon being pressured, Brianna admits to finding the body of Alice. Believing her sister to be Alice's killer, Brianna hid the body in fear of Bethany being imprisoned again. It was during the effort to hide Alice's body that Brianna fell on the funnel web. Brianna also reveals that it was not the neighbours who reported Bethany’s stealing, but rather, her.
During this, Falk notices Lauren and Alice’s respective daughters bickering nearby. He deduces that Alice’s daughter had routinely bullied Lauren’s daughter for years. Upon confronting Lauren with his suspicions, she confesses her frustration with Alice turning a blind eye to her child’s bullying. Subsequently, Lauren had confronted Alice while she was attempting to call Falk, resulting in the pair arguing, and Alice falling and hitting her head on a rock. Believing Alice to just be dazed, Lauren went back to the cabin, and when she returned, Alice was gone, having been moved by Brianna. Convinced by Falk to confess her actions to the police, Lauren attempts to walk away from the waterfall, yet slips and falls, prompting Falk to dive in and save her.
As Brianna and Lauren are escorted away by police, Bethany admits to Falk that Daniel had believed her to be the whistle blower rather than Alice, and that Alice had been attempting to protect her. She then hands over the thumb drive containing the information that Falk had requested from Alice. As a result, Daniel will finally face justice for his money laundering.
