A mixed motif involving spies, revolutionaries, a murdered physicist, an English professor haunted by an indiscretion in a boy's school and a four-nation fissure. Eric Mather, a forced accomplice in what he believes is a Cuban coup, is overwhelmed by his friend Peter Bradley's death. His search for the killers runs parallel to that of Lieutenant Marks who finds a prime suspect in the sensitive Mather. But, although Marks regards Mather as acting the dupe, Mather doesn't realize that his ex-partners are themselves the foils in a much bigger ploy. The sought-after secret contains a code within a code. Miss Davis has produced a coup within a coup.