creature known as a "crawler." Holly is killed when a crawler attacks and bites through her throat. Sarah runs and falls down a hole, where she is knocked unconscious. Juno, trying to prevent Holly's body from being dragged away, kills a crawler with her pickaxe but then, startled and in shock, accidentally strikes Beth through the neck. Beth collapses with Juno's pendant in her hand and begs Juno not to leave her, but a traumatized Juno flees. Sarah awakens to find herself in a den of human and animal carcasses, witnessing Holly's body being mauled and eaten by crawlers. Juno discovers cave markings from previous explorers that point to a specific path through the caves. Juno locates Sam and Rebecca. Sam has deduced that the crawlers are blind and rely on sound to hunt. Juno tells them about the markings, but she will not leave without Sarah. Meanwhile, Sarah encounters Beth, who tells her that Juno wounded then abandoned her. Beth gives her Juno's pendant, telling her it is a gift from Paul, and realizes that Juno and Paul had an affair before his death. Beth begs Sarah to euthanize her, which Sarah reluctantly does by bashing her head in with a rock. Sarah then encounters several crawlers and manages to kill them all, falling into a blood-filled pond in the process and emerging covered in blood. Elsewhere, Juno, Sam and Rebecca are pursued by a large group of crawlers. They reach a chasm and Sam tries to climb across, but a crawler scaling the ceiling attacks and rips her throat out. Sam stabs it before bleeding to death in front of Juno and Rebecca. Rebecca is then dragged away and eaten alive as Juno escapes. Juno encounters Sarah and lies to her about seeing Beth die. After defeating a group of crawlers close to the exit, Sarah confronts Juno, revealing the pendant and her knowledge of Beth's fate and the affair with Paul. Sarah then strikes Juno in the leg with a pickaxe and leaves her to die as a swarm of crawlers approaches. Juno is last heard screaming as Sarah escapes. Sarah falls down a hole and is knocked unconscious. When Sarah awakens, she sees sunlight and clambers up a slope covered in bones to escape the cave. After exhaustedly running to her car, she speeds out of the woods before she pulls over to the side of