Adric first appears in the Fourth Doctor serial
Full Circle. Attempting to escape from the mistfall threatening his community, he stumbles across and finds refuge in the
TARDIS, which has been drawn into E-Space via a
wormhole-like phenomenon known as a Charged Vacuum Emboitment. He stows away when the Doctor,
Romana and
K9 Mark II leave Alzarius and becomes a companion in the following serial,
State of Decay, accompanying them on the rest of their adventures in E-Space. He remains with the Doctor when Romana and K-9 leave and the TARDIS finds its way back into its own universe. With a brilliant mathematical mind and wearing a star-shaped badge for mathematical excellence, Adric is well aware of his own intelligence. This, coupled with his relative immaturity, leads to a personality that is abrasive and occasionally crosses over into arrogance. However, Adric also seeks validation from the Doctor and those around him, and is often hurt and resentful if he feels he is being sidelined or unable to contribute. As an Alzarian, Adric is a member of a highly adaptable species, theoretically capable of genetically evolving to suit any environment, although it is unknown whether his particular substrain is capable of this. It is known that he possesses an inhumanly rapid rate of healing, though not to the extent he can regenerate amputated body parts. Adric is present when, during the events of
Logopolis, the Fourth Doctor falls from the Pharos Project
radio telescope and
regenerates into his fifth incarnation. He continues to travel in the TARDIS along with new companions
Nyssa and
Tegan, but his travels come to an end in
Earthshock when he tries to stop a
Cyberman-controlled freighter from crashing into Earth. The navigational controls are locked by logic codes, and Adric is entering the solution to the last code when the computer is destroyed by a dying Cyberman. He dies in the crash, while his crewmates watch in horror on the TARDIS viewscreen. His last words before the explosion kills him are "Now I'll never know if I was right." Adric dies not knowing that the freighter he was trying to stop would become the "meteor" that would wipe out the dinosaurs even though it obviously pains him. In an effort to stop Nyssa and Tegan from travelling further, the
Xeraphin try to use an illusion of Adric, pleading that if they travelled further they would kill him. They see through the deception when they realise Adric is still wearing his badge (which the Doctor had destroyed in order to kill the Cyber Leader) and travel forth, giving Adric another illusory death scene. Adric also appears as a hallucination at the end of
The Caves of Androzani, and his name is the last word that the Fifth Doctor says before regenerating into the
Sixth Doctor. Decades later, in
The Power of the Doctor, Tegan works to help UNIT fight back an invasion of Cybermen. An artificial intelligence projection of the
Thirteenth Doctor appears before assuming the form of the Fifth Doctor. The two reconcile, with the Doctor assuring Tegan he has not forgotten about any of his companions. Tegan asks what the Doctor thinks is on her mind when surrounded by Cybermen. "Adric," the Doctor responds. ==Appearances in other media==