“Diamond Cartel” (*1/2 out of four) was an incoherent underworld melodrama about a ruthless mob boss (Armand Assante) who makes a deal to buy a diamond from a Hong Kong triad crime boss but is set up and robbed by one of his own which leads to a multitude of double-crossings and shootouts. Everyone has to pay the bills but what a waste of Assante, Michael Madsen (who is only in one scene), and Peter O’Toole of which this was sadly his final film. What a bloody mess.