Once again, the steering of the TARDIS proves a bit unreliable as the Mandragora Helix lures it to Earth and to the realm of "Duke Giuliano" (Gareth Armstrong) who has only just recently inherited his title and thereby earned the enmity of "Count Federico" (Jon Laurimore). Now we know that when out time travellers arrive, that is always a precursor to a mystery and this time, the "Doctor" (Tom Baker) and "Sarah Jane" (Elisabeth Sladen) find themselves embroiled in the mysticism of the menacing "Brethren of Demnos". When "Sarah Jane" falls prey to this cult of black-clad people under the increas...