L'inarrestabile killer

Where does Evil take root? Is there a precise point in our brain where aggression is formed? Yes, and a scientist found it; but it would have been much better for him if he had never tried to investigate things which are best kept secret. After making his sensational discovery, in fact, a sudden and apparently unmotivated impulse pushes him to massacre his wife and then take his own life. Martin Mystère tries to discover the truth, with the help of a true expert in evil: a professional killer seeking revenge! Sometimes, the best allies are the ones it makes the most sense to stay away from. It so happens that Martin, busy with the conclusion of his adventure, is assisted in the investigation by a ruthless and tireless killer, a real ace in the hole when the BVZM will have to face a cruel adversary who does not hesitate to endanger Diana's life.