An amazing Mathematician and awkward teenager, Adric was from the E-Space planet Alzarius. After accidentally fleeing into the TARDIS and seeing the life the Doctor lives, he stowed away. Back in our universe, after witnessing the Fourth Doctor’s regeneration, he was captured by the Master and forced to use mathematical power to create Castrovalva – a city-shaped trap to ensnare the new Doctor. Escaping from the Master he faced Terileptils and the Mara, before meeting the Cybermen. He died struggling to gain control of a freighter the Cybermen set on course for 26th Century Earth. Managing to send the freighter back in time, his actions saved many lives but caused the extinction of the dinosaurs.