This episode is irredeemable. From the bad acting, the heavy-handed rehash of ideas that have been explored in previous Doctor Who episodes, and how bored the Doctor seems at everything that happens (I swear, Capaldi takes deadpan to a whole new level), it’s one of the worst episodes I’ve ever seen. The only thing we really learn about the Doctor or Clara is confirmation that yes, Capaldi and Coleman have absolutely zero chemistry on screen.
Skip it. Watch episode “Dalek” from Season One instead. It’s the same theme, executed better, and without the Doctor-is-just-anti-Dalek retcon.