Doc Martin ITV, 9pm

Cold Feet star Hermione Norris makes a guest appearance as the doctor’s old flame, Sophie Trent. She arrives in Portwenn with an intriguing invitation for the GP to speak in London. Downton Abbey’s Mrs Patmore (Lesley Nicol) guest-stars too as a wild swimmer and, also tonight, the arrival of a herbalist leaves the doctor having to pick up the pieces of her dubious medical advice.