[caption id="attachment_145916" align="aligncenter" width="1280"] 'The Woman Who Lived' (Photo: BBC)[/caption]

It is 1651, and the Doctor has to try and help Ashildr deal with the true consequences of becoming immortal, while she plots to be taken into space with the help of a lion-faced alien, and there's a roguish gentleman called Sam Swift the Quick along for the ride.

That's the story, but here are some of the extra references, fine details and historical footnotes that went into "The Woman Who Lived," starting with a moment of future history:

The reference to Terileptils and the Great Fire of London needs a little teasing out. In Doctor Who, the fire was started by a dropped torch in Pudding Lane, when the Fifth Doctor was thwarting a Terileptil attack in 1666 ("The Visitation"), some 15 years after the events in this story. The Tereleptil weapons made a small fire much bigger until it raged out of control, but the person who dropped the torch was, in fact, the Doctor. The interesting thing is that a previous incarnation of the Doctor had already been warned that he had a hand in the fire, as the Fourth Doctor said he'd been blamed for it "Pyramids of Mars." So presumably he met someone who knew of his involvement before he had been involved.

The leather mask with the beak that the Doctor picks up while discussing the Black Death with Ashildr was typical of the sort worn by doctors attending plague victims in the 1600s. The beak part will have been filled with aromatic items—a kind of medicinal potpourri—to prevent picking up the plague from the putrid air. It was widely believed that smells carried disease in the form of miasma. They also wore an outfit of smooth goatskin from the boots to the head.

[caption id="attachment_145917" align="aligncenter" width="1280"] (Photo: BBC)[/caption]

Ashildr admits an affection for drinking pomace wine while reading her journals. Pomace wine is a lower-alcohol beverage made from the leftover pulp, seeds and stems when fruit has already been pressed for its juice. The English coined the word pomace during the medieval era to describe the leftovers from cider manufacture, although there are also red and white pomace wines. Most notable the Italian ripasso wines, a 20th century innovation that uses pomace to transform the flavor of Valpolicella.

Doctor Who fans may not recognize the face of Struan Rodger, who plays Clayton, but his voice is well known, as he lent his deep tones to the Face of Boe.

Highwaymen were indeed considered to be as much folk heroes as notorious devils, and if they appeared unfazed by the fate that awaited them, laughing and joking with the crowd, so much the better for an appreciative audience. Tyburn Tree—located near to what is now the Marble Arch area of central London—was the chief place of execution for the London and Middlesex area. Famous highwaymen who met their end at Tyburn include Claude Du Vall, James MacLaine, and Sixteen-string Jack.

[caption id="attachment_145918" align="aligncenter" width="1280"] (Photo: BBC)[/caption]

The Doctor's strong stance against banter and puns continues, but a little context on the words used might be useful, particularly "dandy prat," the name Sam Swift calls Ashildr. Dandy is the word the First Doctor uses to describe his Third incarnation when they first meet in "The Three Doctors." As for prat, it's a 16th century term for the buttocks—hence pratfall: to fall on your backside—prat also became a British slang term for a fool or an idiot in the 20th century. Naturally the TARDIS's translation matrix will have converted that from something more timely, such as doddypol or geck.

Ashildr's choice of nickname for her highwayman alter-ego is itself a pun. Highwaymen were also known as "knights of the road," and she's known as The Knightmare. And as a mare is a female horse, there's a hint of the Knightmare's gender there too. Very, very clever.

More evidence of the Time Lord appreciation for British Children's TV, the Doctor refers to Leandro as Lenny the Lion. The original Lenny was created by the ventriloquist Terry Hall in 1954, becoming a TV star in the late '50s and throughout the '60s. He even had his own pop music TV show, entitled Pops and Lenny, on which The Beatles made one of their earlier appearances in 1963.

https://www.youtube.com/watch?v=juqeKTHfJXI

His other anachronous references include Zorro (another masked outlaw, but not created by Johnston McCulley until 1919 and on an entirely different continent) and Scotland Yard. In the 19th century, the Metropolitan Police set up their first headquarters in 4 Whitehall Place, London, and the building had a rear entrance in a short road called Great Scotland Yard, which is how the force gained the metanymic nickname. It's thought there was a medieval palace in the area that was used to house visiting Scottish kings, but by 1651 the area will have been used for government offices. The Doctor did, however, get a little closer with that mention of a victory medal from the Battle of Dunbar—September 3, 1650, one year before the events in this story—in which Oliver Cromwell beat Scottish forces loyal to King Charles II.

Ashildr makes use of a fine piece of British slang when describing her literal escape from the grave as a medieval queen. To "do a bunk" means to run away or escape before being caught, so when she tells the Doctor she "did a bunk before the evisceration," she means she escaped before her bowels are ritually removed—presumably as part of a mummification process.

NEXT: 10 Things You May Not Know About ‘The Zygon Invasion’

Now go back and read the entire 10 Things You May Not Know About Doctor Who archive.