“Those who have felt that the 12th Doctor has been overly dour throughout his time will find much to cheer about, particularly in the last act of the episode”

“It switches tone in a way we’ve not seen done with quite so much panache since the Russell T Davies era, and it’s a relief to say that it works well.”

“Verdict: Capaldi and Coleman confirm what a strong TARDIS team they are in a story that takes a very typical Doctor Who trope and gives it some rather unusual twists. 9/10”

– the review has been taken down (x) but I will edit this with the link when it comes up.