• The Doctor and Bill arrive beside the frozen Thames on Friday 4 February 1814 – the fourth and penultimate day of the final Frost Fair, following impromptu carneys in 1683-84, 1716, 1739-40 and 1789.
• It’s not impossible that another Doctor, his wife and a multi-million-selling Motown musician are also in the vicinity throughout. In A Good Man Goes To War (2011), River Song (Alex Kingston) described how the Eleventh Doctor (Matt Smith) had taken her “ice skating on the River Thames in 1814, the last of the great Frost Fairs” as a birthday treat – and he’d brought Stevie Wonder to sing for her, too! And since the Twelfth offered Clara Oswald (Jenna Coleman) a trip “to see the Thames frozen over” back in The Caretaker (2014) – perhaps he’s also at risk of running into his current self, along with his previous companion?