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.
Notably, it explored Ng's interactions with the members of Torchwood after the revelation that she was pretending to be Gwen Cooper, and Tyler Steele officially joining the team, after he became homeless.