Arizona-New Mexico, c. 1867. Lt. Mike "Blueberry" intercepts a fugitive with a letter for President Grant. He's soon "volunteered" for a spy mission deep into Mexico. Drafting Red and Jimmy, Blueberry endures beatings, torture, and betrayal to meet Chihuahua Pearl, a dance hall girl and a Federal agent! The prize is a half-million dollars in Confederate gold. Everyone wants it, especially unreconstructed Rebels who want the South to rise again. Blueberry learns the only man who knows where it's buried is locked up - in the toughest prison in Mexico...; Continuing... Red Wooley and Jimmy McClure search. Blueberry is ambushed by bandits and thrown in prison. He finds Trevor/Lindsay, who knows where the Confederate gold is buried. Chihuahua Pearl agrees to marry Gobernador Lopez. Red and Jimmy partner with Rebels. Blueberry and Trevor go over the wall, but are sold out. Until Red's crew rolls down a wagonful of dynamite and a herd of wild steers. Pearl dumps Lopez. Trevor leads everyone to a hidden "swallowhole" oasis, then rides off to dig up the gold...