Role: Teenage mathematical genius, rogue and compulsive nibbler who stowed away on the TARDIS and strangely wasn’t booted out at the first opportunity.
The painful truth: Child geniuses in SF are always irritating. Mop-topped, fresh-faced teen rogues in SF are always irritating. Actors who can’t act are intensely irritating. And in Adric we had all three. The convergence of these elements resulted in a Who companion of unfathomable loathsomeness, whose only two defining character traits were being hungry and being crap.