Dad's secret (The mystery box)

This is a mystery book in which the death of a man leads to the showing up of a certain mystery box which leads to the death of many others and the unraveling of many hidden secrets. The family of the dead man; Mr Eben Jones, works hand in hand with the police to catch the murderer but then discovered that it is beyond a murderer but rather a group of men and women with the name "THE CLOWNS" who have issues with the dead man and are set out to take out their revenge on his family and company, although They leave clues to be found ,but it is almost too late before this is realized. Read on as we find out the mystery behind this mysterious box...