Feel the whiplash. It’s less than three weeks since series nine of Doctor Who climaxed in bold, brilliant, bruising style with the two-punch of “Heaven Sent” and “Hell Bent”. The BBC’s decision to delay this year’s run of episodes means we’ve barely had a chance to breathe after our journey into the darkest corners of the Doctor’s hearts before being plunged into this, the eleventh Christmas special. And let’s be clear – this is Doctor Who set to full-on festive romp mode. It’s a little like stumbling, shell-shocked, out of a trauma recovery centre to find someone raspberrying a party blower in your face.