London, 1851. With the opening of the Great Exhibition at hand, interest in mounting in the engineering triumphs of the railways, but not everyone feels like celebrating. In an audacious attack, the London to Birmingham mail train is robbed and derailed, causing many casualties. Planned with military precision, this crime proves a challenge to Detective Inspector Robert Colbeck who fights to untangle a web of murder, blackmail and destruction.

May 1915. As zeppelin bombs fall on London and with the sinking of the Lusitania, anti-German hysteria reaches fever pitch and attacks on German immigrants surge. Not even the West End of London is immune. Jacob Stein's bespoke tailoring business comes under brutal attack, leaving his safe ransacked, his daughter, Ruth, raped and Jacob dead.

At the end of her first unsuccessful season out in society, Lady Georgiana has all but given up on attracting a suitable man - until she receives an invitation to a masked Halloween ball at Broxley Manor. Georgie is uncertain why she was invited, until she learns that the royal family intends to marry her off to a foreign prince, one reputed to be mad.

March, 1918. British newspapers carry the dreadful news that the German Spring Offensive has begun, with thousands of British lives lost. Detective Sargeant Joe Keedy is awaiting release from hospital in London and is anxious to resume the fight against crime on the Home Front. Late one night, a bank is raided by a gang and the villains escape by car with a sizeable haul. Detective Inspector Harvey Marmion is put in charge of the case, but without Keedy at his side he faces an uphill battle to solve this perplexing case.

September, 1940. The sun is shining, and in the midst of the good weather Londoners could be mistaken for forgetting their country was at war - until the familiar wail of the air-raid sirens heralds an enemy attack. The Blitz has started, and normal life has abruptly ended - but crime has not. That night a man's body is discovered in an unmarked van in the back streets of West Ham. When Detective Inspector John Jago is called to the scene, he recognises the victim: local justice of the peace Charles Villiers. The death looks suspicious, but then a German bomb obliterates all evidence.