Rosemary talks to four Northlanders who used archaeological research and investigation techniques to piece together a picture of ‘Fortress Northland’; a staggering network of defence infrastructure which was constructed in panicked haste following the Japanese bombing of Pearl Harbour in December 1941. Jack Kemp, Bill Guthrie, Bill Edwards and James Robinson share tales of what they discovered through archaeological investigations, oral history interviews, and detective work in the archives.