Spoilers are precisely defined here. Rules vary by the story's medium. Info from television stories can't be added here until after the top or bottom of the hour, British time, closest to the end credits roll on BBC One. Therefore, fans in the Americas who are sensitive to spoilers should avoid Tardis on Sundays until they've seen the episode.
Travelling Companions - Adric; the prickly Adric was a controversial companion, unpopular with many viewers. The difficult adolescent suffered from erratic characterisation, one moment bright and advanced, the next objectionable.