The War of 576AE, the Skrel were attacking human settlments. This was the beginning. Humans proved to be a formidable opponent. With time, the Skrel's weapons became more advanced, and finally when everything else has failed, they finally released their ultimate weapon the Ursa. The Ursa are nightmare creatures who are bred for warfare, genetically engineered for one purpose: to hunt and kill humans. But, in the end one man found a strategy that would later be known as Ghosting.