[caption id="attachment_145319" align="aligncenter" width="1280"] Doctor Who: 'Before the Flood' (Photo: BBC)[/caption]

In "Before The Flood" we see the Doctor fiddling about with cause and effect and the passage of time like a true master (although not, it must be noted, like THE Master). He has to go back in time to prevent something nasty from happening, only to discover he plays quite an active role in that thing coming to pass in the first place.

Here are 10 items of wider context for anyone who has already seen the show. It's a bit spoilery, but not overmuch:

• The Doctor's habit of thinking out loud as if teaching a lesson (and indeed, instruct his imaginary class to Google something) is not the first time he's addressed the audience at home directly. There have been a couple of momentary glances down the lens down the years, not least at the beginning of "Listen." The Fourth Doctor mused "even the sonic screwdriver won't get me out of this one" in "The Invasion of Time" and appeared to be talking directly to the viewers, and the First Doctor even wished "a happy Christmas to all of you at home!" at an appropriately festive moment during an episode of the story "The Daleks' Master Plan" in 1965.

• The Doctor's guitar amp—as first seen on top of a tank in "The Magician's Apprentice"—has the logo of Magpie Electricals, who have become the Whoniverse brand for electrical items since the Tenth Doctor met Mr. Magpie in "The Idiot's Lantern," when his TV sets began stealing people's faces, as part of a diabolical plan by the Wire. His company even ended up supplying Starship UK, as seen in the Eleventh Doctor's second adventure "The Beast Below."

• And of course the amp was used partly to demonstrate the Doctor's ability to play Beethoven's Fifth, but also to lead into a hard rock version of the Doctor Who theme, as arranged specially by Murray Gold. This was one of a handful of occasions in which a one-off version of the theme has been used, including both the 25th anniversary special "The Five Doctors" and the 50th anniversary special "The Day of the Doctor":

https://www.youtube.com/watch?v=VKKy-r8tq8c

• Now, to the Fisher King, whose name precedes him in the ancient myths of the British Isles. According to Arthurian legend, the Fisher King (also known as the Wounded King) is the last keeper of the Holy Grail. He has been in some way incapacitated in battle and can no longer walk, nor sire an heir to continue his holy task. As the Fisher King's health declines, so does that of his kingdom, until it is reduced to a wasteland and he only survives on fish from the river. Knights come and try to heal him, but only those chosen by God can help. This story may derive from similar tales of wounded leaders with magical chalices or urns, such as the Celtic Bran the Blessed.

• In Doctor Who, the Fisher King has been created from three components. His spoken voice belongs to the British comedian Peter Serafinowicz, who has appeared in Shaun of the Dead, and lent his voice to Darth Maul in Star Wars: The Phantom Menace. That scream, however, belongs to Corey Taylor of the band Slipknot:

[bbca-brightcove videoid="4539868173001"]

• Physically, the Fisher King is played by Neil Fingleton. Neil, a former basketball player who is 7ft 7.56 inches tall, is the tallest British-born man, and currently the tallest man in the European Union. His unique talents have brought him work as the giant Mag the Mighty in Game Of Thrones, as well as roles in Jupiter Ascending, 47 Ronin and X-Men: First Class.

[bbca-brightcove videoid="4539913892001"]

• The Doctor uses the phrase "I've had a good innings" to describe the quality of his life. It's a term derived from cricket (the Fifth Doctor's favorite sport), where an innings is the amount of time a batsman continues to play without being caught or bowled out by the opposing team. A good innings is one that lasts a long time and scores many runs, therefore the term is often used in British conversation when fondly talking about the length and quality of someone's life. Like this:

"I was so sorry to hear your grandmother passed away."

"Thank you, she was a game old thing, and at 93 you can't say she didn't have a good innings."

• Prentis the Tivolian undertaker (played by Paul Kaye) mentions that his home world has been taken over by Arcateenians. This is a race that has troubled both Sarah Jane Smith (in "Invasion of the Bane," the pilot episode of The Sarah Jane Adventures) and Torchwood (in "Greeks Bearing Gifts").

[caption id="attachment_145321" align="aligncenter" width="1280"] (Photo: BBC)[/caption]

• The Doctor is clearly a big fan of Joseph Haydn, as two of the albums in his record pile contain his music, and they're on the top of Beethoven's Fifth, suggesting that he's been listening to them more recently.

• In discussing the rules around time travel, the Doctor refers to any change in history, no matter how small, having a ripple effect on the future. It's a theme he has dwelled upon a few times—as one might expect of an expert in this field. But the most beloved instance of fans of classic Who occurred in this lovely scene from "Remembrance of the Daleks" in which the Seventh Doctor chats to the owner of a small cafe (played by Joseph Marcell, who also played the butler Geoffrey in The Fresh Prince of Bel Air) about the potential significance of every tiny decision:

https://www.youtube.com/watch?v=Blzpa5oyUVg

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