A DI Hardcastle Investigation--June 1917. Ernest Hardcastle, head of the
Whitehall CID, is called to investigate the murder of Sir Nigel Strang,
permanent secretary at the Ministry of Munitions, in his office.
Given his work, Hardcastle wonders whether the Germans might be
responsible. Then another murder leads Hardcastle to a worker at
Woolwich Arsenal, who is suspected of passing information to the enemy.
But is there a connection? Hardcastle must find out...