To Kill A Devil: A Mason Collins Crime Thriller 4

1946 Vienna. When a shadowy organization fails to assassinate Mason Collins, they go after his colleagues, his friends, and the love of his life. Mason knows the only way to stop the killings is to cut off the head of the snake.
Armed only with the alias, Valerius, Mason treks across Franco's Spain to war-torn Vienna to eliminate the man ordering the hits. But tracking him down seems to be an unsurmountable task; everyone speaks his name with awe and fear, but no one knows if he's real or a gangland myth.
Mason, desperate for answers, abandons his strict moral code, leading him down a very dark path, and to succeed in hunting one devil, he makes a pact with another.
But what Mason doesn't know is that, even if he does find his way in the darkness, the man they call Valerius has something special in store for him.
To Kill a Devil brings post-World War Two Vienna to life in vivid detail, and if your tastes include a hero who is one part Harry Bosch and one part Jack Reacher, then you'll love this noirish tale of intrigue and revenge.