Upon Levi’s arrival, outgoing guard J.D. warns him that no one ever leaves the post alive; moments later, J.D.'s relief helicopter is shot down by Bartholomew’s strike team, revealing sentries are disposable loose ends slated for execution. When Drasa is pulled down into the abyss during a breach, Levi rappels into the fog to save her. Below, they discover the Gorge houses an abandoned World War II biological weapons laboratory co-opted by private defense conglomerate Darklake, and the "Hollow Men" are human subjects mutated by decades of rogue mutagenic gene-editing.
Command activates the "Stray Dog" protocol—a scorched-earth fail-safe meant to incinerate the canyon, obliterate genetic evidence, and execute both operatives. After battling mutated creatures and mercenary kill squads, Levi and Drasa overload the facility's reactors to trigger a massive detonation. They escape the collapsing ravine, fake their deaths, and fulfill their promise by reuniting in freedom at an outdoor café in Èze, France.