1943 and the end of retreat for Britain and her allies, as the war is carried into enemy territory From captured bases and makeshift harbours in North Africa, the Royal Navy's Special Force is the probe and spearhead of the advance To this unorthodox warfare comes the corvette 'HMS Thistle' and the commanding officer, John Crespin and soon they are fighting among remote Adriatic islands, helping partisans and guerillas overwhelm their enemy