Yes, in the movie "Unthinkable," there is indeed a fourth bomb. The plot revolves around a terrorist, played by Michael Sheen, who has planted three nuclear bombs in major U.S. cities. As the story unfolds, it is revealed that there is a fourth bomb that he has hidden from the authorities. This twist heightens the tension and urgency as the characters race against time to prevent a catastrophic event. The film explores themes of morality, torture, and the consequences of extreme measures in the face of terrorism.

The movie "Unthinkable" revolves around the moral and ethical dilemmas of torture and national security. It follows an FBI agent and a military interrogator who are tasked with extracting information from a captured terrorist who has planted nuclear bombs in U.S. cities. The film explores themes of justice, the limits of morality in the face of imminent danger, and the psychological toll of extreme interrogation methods. It raises questions about how far one would go to protect innocent lives and the consequences of such decisions.

In the end of "Unthinkable," after a tense and morally complex interrogation, the protagonist, FBI agent Helen Brody, is faced with a devastating choice. The film culminates in the revelation that the captured terrorist, Yusuf, has planted nuclear bombs in three U.S. cities. Despite the efforts to extract information, the bombs are detonated, resulting in catastrophic loss of life. The ending leaves viewers questioning the ethics of torture and the sacrifices made in the name of national security, emphasizing the moral ambiguity of the characters' actions.

As of my last update in October 2023, "Unthinkable," a thriller film starring Samuel L. Jackson, Carrie-Anne Moss, and Michael Sheen, is not available on Netflix. Availability can change, so it's best to check Netflix directly or use a streaming guide for the most current information regarding its streaming status.