Delving into the Earth's depths, a soldier named Harris stumbles upon a monstrous secret. After encountering a colossal, fire-breathing entity and witnessing the tragic sacrifice of his leader, Ripley, Harris escapes with a team on the brink of despair. Their harrowing journey takes them through treacherous tunnels, culminating in a face-off with a clandestine UN task force, AEGIS. Rescued but emotionally scarred, Harris finds himself torn between his duty to protect humanity from these subterranean nightmares and his desire to return to his family. As he grapples with this internal conflict, a new threat emerges - another gateway, another potential monstrosity waiting to be unleashed. Forced back into the fray with a new leader at the helm, Harris must confront his fears and fight for the world's survival, all while battling the lingering trauma of his previous encounter and the weight of a promise made to his worried family.