A deep-space probe has returned intelligence: the Bydo Empire is preparing a full-scale assault on Earth. A conventional attack force would be detected immediately by the Bydo's long-range scanners, ending any chance of surprise. The only viable approach is a single pilot in a single R-Type fighter, threading through the Bydo defense network alone, without backup. If the Empire's preparations can be destroyed before the attack launches, the Earth survives. If not, it does not.