In a future where the United Nations has been established for fifty years, tensions between the UN and the Com-Pubs (Communist Publics) escalate as Thorn Hard, a high-level flier for the Pacific Watch, finds himself off duty on a romantic outing with his fiancée, Sylva West. Their peaceful moment is shattered when Thorn receives an urgent report about unidentified high-speed traffic approaching Earth, suspected to be Martian spacecraft. As he investigates, a massive, unfamiliar rocket ship lands nearby, and Thorn's communication devices are abruptly disabled by a mysterious blue flash. Thorn and Sylva soon discover they are trapped within an invisible dome of force created by the Com-Pubs, who have landed on United Nations territory under the guise of Martian invaders. The Com-Pub leader, Kreynborg, captures them and reveals his plan to use the dome to trap the UN's fighting fleet, which is rendered helpless against the barrier. Kreynborg intends to starve the trapped forces into submission while he enjoys the company of Sylva, whom he has taken a liking to. As the UN fleet gathers outside the dome, unaware of the true nature of the threat, Thorn and Sylva attempt to escape. They face numerous challenges, including Kreynborg's relentless pursuit and the suffocating gas he deploys to capture them. Thorn's ingenuity leads him to devise a plan to signal the UN fleet for help, but time is running out as Kreynborg prepares to execute his plan for domination. In a desperate bid for freedom, Thorn manages to short-circuit the induction screen separating him from Sylva, allowing them to escape Kreynborg's clutches. They work together to create a signal fire, hoping to attract the attention of the UN fleet. However, their efforts are complicated by Kreynborg's helicopter patrols and the ever-looming threat of the Com-Pub fleet. As the situation escalates, Thorn confronts Kreynborg directly, using a makeshift weapon to incapacitate him and disable the dome's control mechanism. With the barrier down, the UN fleet is finally able to engage the Com-Pubs in a fierce battle. Thorn and Sylva emerge victorious, having thwarted Kreynborg's plans and saved their nation from invasion. The narrative explores themes of love, bravery, and the struggle against tyranny, culminating in a high-stakes confrontation that tests the characters' resolve and ingenuity. The story serves as a cautionary tale about the dangers of complacency in the face of external threats and the importance of unity in overcoming adversity.
By Murray Leinster · First published 1953 · Genre: Science Fiction, Adventure, Thriller