Silk follows a set of barristers from a chambers in London. The series' main focus is on Martha Costello (Maxine Peake) and her ambition to become Queen's Counsel as well as on her rival, Clive Reader (Rupert Penry-Jones), and the chambers' two new pupils, Niamh Cranitch (Natalie Dormer) and Nick Slade (Tom Hughes). The chambers' senior clerk, Billy Lamb (Neil Stuke), also features heavily.