"A Fourth Wave: The End?" is the last chapter in the lives of Shelby and Simon on their quest to help rid, or at least salvage, society from the pandemic. Their relationship ups and downs seem to come to a close with the pandemic, but the world has other plans. A war breaks out, throwing them into a situation that no one has encountered before. Will the characters maintain their sense of hope during these difficult times, or will they finally succumb to the trauma of the pandemic? Will Shelby and Simon finally get their happy ending? Will their humanitarian approach to life be defeated? Will the world learn from what it has been through, or will society set itself up for further chaos? Will lives around the world ever be the same? The characters all try to live with a sense of hope throughout the story, wondering if it will be enough.