Archaeologists Tony Pollard and Neil Oliver travel to the White Cliffs of Dover in search of clues to one of the forgotten conflicts of World War Two - the Battle of the Big Guns, which lasted from 1940 to 1944. After they set up their HQ, the pair search for evidence of Winnie and Jane, two of the long-range British weapons which fired across the Channel, and visit France to see their German counterparts.