When Detective Steven Nimh who infiltrated the organization of Billy Lo and has given Walker very useful information about Lo's operations. Walker feeling that Lo might be suspecting that he has a mole in his organization wants Nimh to pull out. But Nimh sensing that something big is going down decides to stay in. But Lo sets him up and is killed. So Walker with what info Nimh gave them tries to get Lo. At the same time Nimh's father who's a friend of Walker's comes and tries to help his grandson deal with his loss and some other problems.