General Carrington sent XIII to hide himself for a time among the SPADS elite troops under the name of Tanner, but soon Colonel Amos discovers that the general falsified pieces of dossier XIII, that in fact this mysterious amnesia would ultimately be a certain Jason Fly who would have undergone surgery to resemble the late Steve Rowland who would have participated in the murder of President Sheridan a few months earlier. The mission of this Jason Fly was simple, he was to allow the general and his high-ranking allies to gradually dismantle the plot and discover who was hiding behind the mysterious "numbered" chiefs who were pulling the strings of all this. However XIII, accompanied by beautiful Jones and Sergeant Betty, will have to flee the troops of Colonel Mc Call launched in pursuit of him.