Will the most powerful defense system in history be used to safeguard America—or to force universal domination? The U.S. has unleashed Thor's Hammer, a missile-launching satellite that can strike anywhere on the planet in seconds. But when President Joseph Gardner elects to employ the still-untested weapon against terrorists firing missiles at Indian cities, the Hammer misses its mark, killing thousands of Pakistani civilians. In retaliation, Pakistan and its neighbors grant China a strategic naval advantage over America through access to Middle Eastern ports. China responds swiftly and brutally, attacking and occupying Somalia, then setting up missile pads to target U.S. naval ships across vital sea-lanes. While in Earth's orbit, Chinese and Russian spacecraft surround an American space station with one clear message: back down or watch as your navy is crippled. With a president battling for his political life in D.C., retired Air Force Lieutenant General Patrick McLanahan and Kai Raydon, commander of the U.S. Space Defense Force, race to defuse the crisis—as every second brings the world closer to a full-scale war of superpowers on Earth . . . and miles above it.