Present day: A postal worker and a customer are found murderedin a rural Montana post office. U.S. Postal Inspectors Gillian Loomis and Max Dombrowski are ordered to investigate the brutal crime. Max isn’t thrilled. He’d rather be working in a city than in the boondocks. His new partner, this Loomis person…well, they say she killed someone by accident. Great. And she doesn’t seem thrilled with him, either. But neither has much choice. It’s this or worse.
When they start looking for evidence, they uncover the existence of three letters written in 1918 by a man named Sharpless Walker. Somehow, those letters are connected to the murders.
As Gillian and Max follow the trail of the letters, searching for a motive for the murders, one by one the enigmatic missives disappear, leaving violence and destruction in their wake. Something about these letters is bringing death to all who touch them. When Gillian and Max locate the last letter, encrypted in World War I code, they realize they have made themselves the next targets of whoever is destroying the letters and those who hold them.
Somehow the letters are connected to the Lusitania. Whatever dark secret was buried with Sharpless Walker won’t stay buried. Gillian and Max just hope they can figure out the connection before the two of them become the final victims. To do this, they must unravel a sinister conspiracy behind one of the most shocking acts of the early twentieth century.