Moriarty and the Massacre of Mammon

Moriarty, the 'Napoleon of Crime', is no longer satisfied with private enterprise. In the summer of 1915, he finds an opportunity to expand his business through a secret collaboration with 'The Other Mr M' by investing the profits of his criminal empire into financing the war. Both sides of the war.
Together, Moriarty and the other Mr M prolong the war for another three years, with reparations being paid for another century. And a body count that goes into the millions... And all that without firing a single shot. The men of finance are safe.
This dark but clever tale of plotting and counter-plotting villains, vulnerable young men and street-wise women is set in various parts of London, including a certain 'House of Velvet', a deceptively peaceful suburban garden, and the silent chamber of Emmeline, Moriarty's chief accountant. It also involves a famous work of art.
But who is the mysterious 'Mr M'? Who, ultimately, has the upper hand in this most profitable of all deals? And what will happen when the war ends?
Moriarty, by the way, has nothing but the deepest contempt for the 'insignificant detective' who introduced him to the world. And he is determined to beat Napoleon at his own game.