'Twas vintage Dr Who and I loved every minute of it. As my sister said, it was all the better because it required you to think.
It was also clever and humorous, exciting and scary, and blissfully free of loud, effects-heavy action scenes where everyone screams hysterically. Fantastic.
So what purpose did this episode serve, other than filler?
Incredibly good, high-quality entertainment, Wendy.
Yvonne
